CELEX: 62021CJ0410
References for a preliminary ruling
Migrant workers
Social security
Legislation applicable
Regulation (EC) No 987/2009
Article 5
A1 certificate
Provisional withdrawal
Binding effect
Certificate fraudulently obtained or relied on
Regulation (EC) No 883/2004
Article 13(1)(b)(i)
Persons normally pursuing an activity as an employed person in two or more Member States
Applicability of the legislation of the Member State in which the registered office is situated
Concept of ‘registered office’
Undertaking which has obtained a Community licence for transport under Regulation (EC) No 1071/2009 and Regulation (EC) No 1072/2009
Effect
Licence fraudulently obtained or relied on

These requests for a preliminary ruling concern the interpretation of Article 13(1)(b)(i) of Regulation (EC) No 883/2004 of the European Parliament and of the Council of 29 April 2004 on the coordination of social security systems (OJ 2004 L 166, p. 1), as amended by Regulation (EU) No 465/2012 of the European Parliament and of the Council of 22 May 2012 (OJ 2012 L 149, p. 4) (‘Regulation No 883/2004’), of Article 5 of Regulation (EC) No 987/2009 of the European Parliament and of the Council of 16 September 2009 laying down the procedure for implementing Regulation No 883/2004 (OJ 2009 L 284, p. 1) as amended by Regulation No 465/2012 (‘Regulation No 987/2009’), of Article 3(1)(a) and Article 11(1) of Regulation (EC) No 1071/2009 of the European Parliament and of the Council of 21 October 2009 establishing common rules concerning the conditions to be complied with to pursue the occupation of road transport operator and repealing Council Directive 96/26/EC (OJ 2009 L 300, p. 51), and of Article 4(1)(a) of Regulation (EC) No 1072/2009 of the European Parliament and of the Council of 21 October 2009 establishing common rules for access to the international road haulage market (OJ 2009 L 300, p. 72).
Those requests have been made in two sets of criminal proceedings brought, first, against FU and DRV Intertrans BV (Case C‑410/21), and, second, against Verbraeken J. en Zonen BV and PN (Case C‑661/21), for fraud committed in respect of social security contributions.

Legal context

Regulation No 883/2004
Recital 15 of Regulation No 883/2004 states:
‘It is necessary to subject persons moving within the Community to the social security scheme of only one single Member State in order to avoid overlapping of the applicable provisions of national legislation and the complications which could result therefrom.’
Title II of Regulation No 883/2004, entitled ‘Determination of the legislation applicable’, comprises Articles 11 to 16 thereof.
Article 11(1) of that regulation provides:
‘Persons to whom this Regulation applies shall be subject to the legislation of a single Member State only. Such legislation shall be determined in accordance with this Title.’
Article 13(1) of that regulation is worded as follows:
‘A person who normally pursues an activity as an employed person in two or more Member States shall be subject:
…
(b)      if he/she does not pursue a substantial part of his/her activity in the Member State of residence:
(i)      to the legislation of the Member State in which the registered office or place of business of the undertaking or employer is situated if he/she is employed by one undertaking or employer; …
…’
Under Article 72(a) of that regulation, the Administrative Commission for the Coordination of Social Security Systems (‘the Administrative Commission’) is responsible, inter alia, for dealing with all  administrative questions or questions of interpretation deriving from the provisions of Regulation No 883/2004 or from those of Regulation No 987/2009.
Article 76 of Regulation No 883/2004, headed ‘Cooperation’, provides:
‘…
4.      The institutions and persons covered by this Regulation shall have a duty of mutual information and cooperation to ensure the correct implementation of this Regulation.
…
6.      In the event of difficulties in the interpretation or application of this Regulation which could jeopardise the rights of a person covered by it, the institution of the competent Member State or of the Member State of residence of the person concerned shall contact the institution(s) of the Member State(s) concerned. If a solution cannot be found within a reasonable period, the authorities concerned may call on the Administrative Commission to intervene.’
Article 90(1) of that regulation provides:
‘[Council Regulation (EEC) No 1408/71 of 14 June 1971 on the application of social security schemes to employed persons, to self-employed persons and to members of their families moving within the Community (OJ, English special edition, Series I, 1971(II), p.416)] shall be repealed from the date of application of this Regulation.
…’

Regulation No 987/2009
Recitals 2 and 6 of Regulation No 987/2009 state:
‘(2)      Closer and more effective cooperation between social security institutions is a key factor in allowing the persons covered by [Regulation No 883/2004] to access their rights as quickly as possible and under optimum conditions.
…
(6)      Strengthening certain procedures should ensure greater legal certainty and transparency for the users of [Regulation No 883/2004]. …’
Under the heading ‘Legal value of documents and supporting documents issued in another Member State’, Article 5 of that regulation provides:
‘1.      Documents issued by the institution of a Member State and showing the position of a person for the purposes of the application of [Regulation No 883/2004] and of [this Regulation], and supporting evidence on the basis of which the documents have been issued, shall be accepted by the institutions of the other Member States for as long as they have not been withdrawn or declared invalid by the Member State in which they were issued.
2.      Where there is doubt about the validity of a document or the accuracy of the facts on which the particulars contained therein are based, the institution of the Member State that receives the document shall ask the issuing institution for the necessary clarification and, where appropriate, the withdrawal of that document. The issuing institution shall reconsider the grounds for issuing the document and, if necessary, withdraw it.
3.      Pursuant to paragraph 2, where there is doubt about the information provided by the persons concerned, the validity of a document or supporting evidence or the accuracy of the facts on which the particulars contained therein are based, the institution of the place of stay or residence shall, in so far as this is possible, at the request of the competent institution, proceed to the necessary verification of this information or document.
4.      Where no agreement is reached between the institutions concerned, the matter may be brought before the Administrative Commission by the competent authorities no earlier than one month following the date on which the institution that received the document submitted its request. The Administrative Commission shall seek to reconcile the points of view within six months of the date on which the matter was brought before it.’
Article 14(5a), first subparagraph, of that regulation is worded as follows:
‘For the purposes of the application of Title II of [Regulation No 883/2004], “registered office or place of business” shall refer to the registered office or place of business where the essential decisions of the undertaking are adopted and where the functions of its central administration are carried out.’
Article 19(2) of that same regulation provides:
‘At the request of the person concerned or of the employer, the competent institution of the Member State whose legislation is applicable pursuant to Title II of [Regulation No 883/2004] shall provide an attestation that such legislation is applicable and shall indicate, where appropriate, until what date and under what conditions.’
Article 20 of Regulation No 987/2009, entitled ‘Cooperation between institutions’, provides:
‘1.      The relevant institutions shall communicate to the competent institution of the Member State whose legislation is applicable to a person pursuant to Title II of [Regulation No 883/2004] the necessary information required to establish the date on which that legislation becomes applicable and the contributions which that person and his employer(s) are liable to pay under that legislation.
2.      The competent institution of the Member State whose legislation becomes applicable to a person pursuant to Title II of [Regulation No 883/2004] shall make the information indicating the date on which the application of that legislation takes effect available to the institution designated by the competent authority of the Member State to whose legislation that person was last subject.’
Article 96(1) of that regulation provides:
‘[Council Regulation (EEC) No 574/72 of 21 March 1972 laying down the procedure for implementing Regulation No 1408/71 (OJ,  English Special Edition, Series I 1972(I), p. 160)] is repealed with effect from 1 May 2010.
…’

Regulation No 1071/2009
Article 3 of Regulation No 1071/2009, entitled ‘Requirements for engagement in the occupation of road transport operator’, provides in paragraph 1:
‘Undertakings engaged in the occupation of road transport operator shall:
(a)      have an effective and stable establishment in a Member State;
…’
Under the heading ‘Conditions relating to the requirement of establishment’, Article 5 of that regulation is worded as follows:
‘In order to satisfy the requirement laid down in Article 3(1)(a), an undertaking shall, in the Member State concerned:
(a)      have an establishment situated in that Member State with premises in which it keeps its core business documents, in particular its accounting documents, personnel management documents, documents containing data relating to driving time and rest and any other document to which the competent authority must have access in order to verify compliance with the conditions laid down in this Regulation. Member States may require that establishments on their territory also have other documents available at their premises at any time;
(b)      once an authorisation is granted, have at its disposal one or more vehicles which are registered or otherwise put into circulation in conformity with the legislation of that Member State, whether those vehicles are wholly owned or, for example, held under a hire-purchase agreement or a hire or leasing contract;
(c)      conduct effectively and continuously with the necessary administrative equipment its operations concerning the vehicles mentioned in point (b) and with the appropriate technical equipment and facilities at an operating centre situated in that Member State.’
Article 11(1) of that regulation provides:
‘A transport undertaking which complies with the requirements laid down in Article 3 shall, upon application, be authorised to engage in the occupation of road transport operator. The competent authority must ascertain that an undertaking which submits an application satisfies the requirements laid down in that Article.’
Article 12(1) of that regulation states as follows:
‘Competent authorities shall monitor whether undertakings which they have authorised to engage in the occupation of road transport operator continue to fulfil the requirements laid down in Article 3. …’

Regulation No 1072/2009
Article 3 of Regulation No 1072/2009 provides:
‘International carriage shall be carried out subject to possession of a Community licence and, if the driver is a national of a third country, in conjunction with a driver attestation.’
Article 4(1) of that regulation provides:
‘The Community licence shall be issued by a Member State, in accordance with this Regulation, to any haulier carrying goods by road for hire or reward who:
(a)      is established in that Member State in accordance with Community legislation and the national legislation of that Member State; and
(b)      is entitled in the Member State of establishment, in accordance with Community legislation and the national legislation of that Member State concerning admission to the occupation of road haulage operator, to carry out the international carriage of goods by road.’

The disputes in the main proceedings and the questions referred for a preliminary ruling

Case
C
‑
/21
FU is the managing director of DRV Intertrans BV, a company established in Belgium. He and his spouse set up the company Md Intercargo s. r.  o., established in Slovakia. The business of both companies is national and international transport.
The competent Slovak authority issued A1 certificates attesting, pursuant to Article 19(2) of Regulation No 987/2009, that several employees of Md Intercargo were affiliated to the Slovak social security system (‘the workers concerned’).
FU’s activities and the links between the abovementioned companies were subject to supervision by the Sociale Inspectie (Social Security Inspectorate, Belgium) (‘the Belgian Social Security Inspectorate’), which found that Md Intercargo was in fact managed from Belgium where most of its transport services took place. According to the Belgian Social Security Inspectorate, Md Intercargo had been set up in order to assign a cheap labour force to DRV Intertrans by posting workers. Although it held a Community licence for road transport  issued by the Slovak authorities, Md Intercargo had no relevant economic activity in Slovakia, which was confirmed by the authorities of that Member State in response to a question from the Belgian Social Security Inspectorate.
On the basis of the checks carried out by the Belgian Social Security Inspectorate, criminal proceedings were brought against FU and DRV Intertrans before the correctionele rechtbank West-Vlaanderen, afdeling Brugge (Criminal Court, Western Flanders, Bruges Division, Belgium) for fraud relating to social security contributions for the period from 17 July 2013 to 11 October 2014.
During those criminal proceedings, on 26 October 2016 the Belgian Social Security Inspectorate requested the Slovak issuing institution to withdraw retroactively the A1 certificates in respect of the workers concerned.
By letter of 20 December 2016, the Slovak issuing institution replied that it had unsuccessfully attempted to carry out an inspection of the company MD Intercargo and asked the Belgian Social Security Inspectorate to send it the results of its investigation and all the evidence gathered in the context of that case in order to enable it to decide whether it agreed  to apply retroactively the Belgian social security system to the workers concerned. In view of its serious doubts as to the true place of the registered office of that company and of the existence of the criminal proceedings referred to in paragraphs 25 and 26 of this judgment, the Slovak issuing institution stated that it would provisionally withdraw all the A1 certificates relating to the workers concerned, with the result that those certificates no longer have binding force and that the Belgian authorities could thus continue those criminal proceedings. However, that issuing institution emphasised, first, that both the evidence which the Belgian Social Security Inspectorate was required to transmit to it and the outcome of the pending criminal proceedings before the Belgian courts would enable it to determine definitively which legislation applied to the workers concerned and, second, that, in the meantime, those workers would remain subject to the Slovak social security system and that none of the A1 certificates at issue would be definitively withdrawn.
By a judgment of 10 May 2017, the correctionele rechtbank West-Vlaanderen, afdeling Brugge (Criminal Court, Western Flanders, Bruges Division) declared FU and DRV Intertrans to be guilty of fraud in respect of social security contributions. That judgment was, first of all, upheld by a judgment of 4 October 2018 of the hof van beroep te Gent (Court of Appeal, Ghent, Belgium), then, set aside by a judgment of 9 April 2019 of the Hof van Cassatie (Court of Cassation, Belgium), which referred the case to the hof van beroep te Antwerpen (Court of Appeal, Antwerp, Belgium).
By a judgment of 11 February 2021 pronounced by the latter court, FU and DRV Intertrans were found guilty of fraud in respect of social security contributions. It is apparent from that judgment that, in view of their temporary withdrawal by the Slovak issuing institution, the A1 certificates at issue in the main proceedings were considered to be non-binding and, therefore, devoid of any evidential value as regards the social security system applicable to the workers concerned. Similarly, it was held that the Community licence for road transport held by MD Intercargo did not affect the determination of that system and did not require it to be considered that MD Intercargo had an effective and stable establishment in Slovakia, for the purposes of Regulations  No 883/2004 and No 987/2009.
FU and DRV Intertrans brought an appeal against that judgment before the referring court, the Hof van Cassatie (Court of Cassation). In that appeal, the appellants in the main proceedings submit in particular that Article 5 of Regulation No 987/2009 does not permit the temporary withdrawal or suspension of the A1 certificates, with the result that the A1 certificates provisionally withdrawn by the Slovak issuing institution remained valid. Second, the appellants in the main proceedings submit that, pursuant inter alia to Articles 5, 11 and 12 of Regulation No 1071/2009 and Articles 3 and 4 of Regulation No 1072/2009, the fact that a company holds a Community licence for road transport constitutes irrefutable evidence of the existence of an effective and stable establishment in the Member State which issued it, and, therefore, of that company’s registered office in that Member State, for the purposes of Article 13(1) of Regulation No 883/2004.
In those circumstances, the Hof van Cassatie (Court of Cassation) decided to stay the proceedings and to refer the following questions to the Court of Justice for a preliminary ruling:
‘(1)      Must Article 5 of [Regulation No 987/2009] be interpreted as meaning that, if, following a request by the authorities of the Member State of employment for the retroactive withdrawal of the “Al” certificates, the authorities of the Member State which issued those certificates confine themselves to withdrawing [them] provisionally, stating that they no longer have any binding force, so that the criminal proceedings in the Member State of employment can continue, and that a final decision will only be taken by the Member State that issued [those certificates] once the criminal proceedings in the Member State of employment have been finally concluded, the presumption attached to the Al certificates that the workers concerned are properly affiliated to the social security system of that issuing Member State ceases to apply and those Al certificates are no longer binding on the authorities of the Member State of employment? If the answer to that question is in the negative, may the authorities of the Member State of employment, in the light of the case-law of the [Court], disregard the Al certificates at issue on the grounds of fraud?
(2)      Must Article 13(1)(b)(i) of [Regulation No 883/2004], Article 3(1)(a) and Article 11(1) of [Regulation No 1071/2009] and Article 4(1)(a) of [Regulation No 1072/2009] be interpreted as meaning that the fact that an undertaking has obtained a licence for road transport in a Member State of the European Union pursuant to [Regulation No 1071/2009] and [Regulation No 1072/2009] and which therefore must have an effective and stable establishment in that Member State, necessarily constitutes irrefutable proof that its registered office is established in that Member State within the meaning of Article 13(1) of [Regulation No 883/2004], for the purposes of determining the applicable social security system and that [in that sense] the authorities of the Member State of employment are bound by that determination?’

Case
C
‑
/21
PN is the managing director of Verbraeken J. en Zonen BV (‘Verbraeken’), a transport company established in Melle (Belgium). In addition, PN is co-owner of UAB Van Daele F. (‘Van Daele’), a company specialising in transport and logistics services established in Lithuania which holds a Community licence for road transport issued by the Lithuanian authorities.
According to an investigation carried out by the Belgian Social Security Inspectorate, PN and Verbraeken used Van Daele to employ Lithuanian drivers in Belgium. The latter, after being recruited in Lithuania, immediately went to Belgium in order to sign their employment contracts and to carry out their activities from that Member State, from the premises of Verbraeken. They drive mainly in Belgium and in neighbouring countries and return to those premises for their compulsory rest periods. The transport documents and tachograph discs are processed by the office of PN in Melle.
Criminal proceedings were brought against PN and Verbraeken for, in particular, fraud in respect of social security contributions in the period from 1 July 2011 to 4 December 2015.
By a judgment of 18 September 2019, the correctionele rechtbank van Oost-Vlaanderen, afdeling Gent (Criminal Court, Eastern Flanders, Ghent Division, Belgium) declared PN and Verbraeken to be guilty of that offence. That judgment was set aside in part by a judgment of 18 March 2021 of the hof van beroep te Gent (Court of Appeal, Ghent) in so far as it declared the facts constituting that offence to be established in respect of PN and Verbraeken for the period from 20 January 2014 to 4 December 2015.
PN and Verbraeken brought an appeal against that judgment before the referring court in which they submitted that, pursuant to Articles 5, 11 and 12 of Regulation No 1071/2009 and Article 4 of Regulation No 1072/2009, the fact that a company holds a Community licence for road transport constitutes irrefutable evidence of the existence of an effective and stable establishment in the Member State which issued it, and, therefore, of that company’s registered office in that Member State, for the purposes of Article 13(1) of Regulation No 883/2004.
In those circumstances, the Hof van Cassatie (Court of Cassation) decided to stay the proceedings and to refer the following questions to the Court of Justice for a preliminary ruling:
‘(1)      Must Article 13(1)(b)(i) of [Regulation No 883/2004], Article 3(1)(a) and Article 11(1) of [Regulation No 1071/2009] and Article 4(1)(a) of [Regulation No 1072/2009] be interpreted as meaning that the fact that an undertaking that has obtained a licence for road transport in a Member State pursuant to [Regulation No 1071/2009] and [Regulation No 1072/2009] and which therefore must have an effective and stable establishment in that Member State, necessarily constitutes irrefutable proof that its registered office is established in that Member State within the meaning of Article 13(1) of [Regulation No 883/2004], for the purposes of determining the applicable social security system and that [in that sense] the authorities of the Member State of employment are bound by that determination?
(2)      May the national court of the Member State of employment which determines that the road transport licence in question has been obtained by fraud disregard that authorisation, or must the authorities of the Member State of employment, on the basis of the finding of fraud, first request the withdrawal of that licence from the authorities which issued the licence?’
By decision of the President of the Court of 13 September 2022, Cases C‑410/21 and C‑661/21 were joined for the purposes of the oral part of the procedure and of the judgment.

Consideration of the questions referred

The first question in Case
C
‑
/21
It is apparent from the request for a preliminary ruling concerning Case C‑410/21 that, following a request for reconsideration and withdrawal of the A1 certificates at issue in the main proceedings, sent by the Belgian Social Security Inspectorate to the Slovak issuing institution, the latter, having doubts as to the facts on the basis of which those certificates were issued and as to the social security legislation applicable to the workers concerned, declared that it was provisionally withdrawing those certificates, which would not have binding force until it determined the social security scheme applicable to the workers concerned and that it would decide, therefore, on the request after the conclusion of the criminal proceedings brought before the Belgian courts against the defendants in the main proceedings for acts that could involve those certificates having been fraudulently obtained and used.
Thus, by ‘provisionally withdrawing’ the A1 certificates at issue in the main proceedings, the Slovak issuing institution intended, ultimately, to suspend the legal effects of those certificates for a specified period.
In those circumstances, it must be held that, by its first question in Case C‑410/21, the referring court asks, in essence, first, whether Article 5 of Regulation No 987/2009 must be interpreted as meaning that an A1 certificate issued by the competent institution of a Member State ceases to bind the institutions and courts of the Member State in which the work is carried out where, following a request for review and withdrawal sent by the competent institution of that latter Member State to the issuing institution, that institution has declared that it has suspended the binding effects of that certificate until such time as it decides definitively on that request. If that first question is answered in the negative, the referring court then asks whether, in such circumstances, a court of the Member State in which the work is carried out, hearing criminal proceedings brought against persons suspected of having fraudulently obtained or used that same A1 certificate, may nevertheless find that there has been fraud and consequently disregard that certificate.
As a preliminary point, it should be recalled that the A1 certificate, which replaced the E 101 certificate provided for by Regulation No 574/72, corresponds to a standard form issued, in accordance with Title II of Regulation No 987/2009, by the institution designated by the competent authority of the Member State whose social security legislation is applicable, in order to certify, in accordance with, inter alia, Article 19(2) of that regulation, that workers who are in one of the situations referred to in Title II of Regulation No 883/2004 are subject to the legislation of that Member State. In so doing, by virtue of the principle that workers must be covered by only one social security system, that certificate thus necessarily means that the other Member States’ social security systems cannot apply  (judgment of 14 May 2020,
Bouygues travaux publics and Others
, C‑17/19, EU:C:2020:379, paragraphs 38 and 39 and the case-law cited).
As the Court has already held, Regulation No 987/2009 codified the Court’s case-law on the scope and legal effects of the E 101 certificate and the procedure to be followed in order to resolve any disputes between the institutions of the Member States concerned regarding the validity or accuracy of that certificate, by laying down, first, the binding nature of those certificates and the exclusive competence of the issuing institution to assess their validity, and by expressly reproducing, second, the procedure for dialogue between the competent institutions of the Member States concerned and reconciliation before the Administrative Commission as a means for resolving disputes between those institutions as regards both the accuracy of the documents drawn up and the determination of the legislation applicable to the worker concerned (see judgment of 6 September 2018,
Alpenrind and Others
, C‑527/16, EU:C:2018:669, paragraph 43 and the case-law cited).
In particular, Article 5(1) of Regulation No 987/2009 provides that documents issued by the institution of a Member State and showing the position of a person for the purposes of the application of Regulations No 883/2004 and No 987/2009, and supporting evidence on the basis of which the documents have been issued, are to be accepted by the institutions of the other Member States for as long as they have not been withdrawn or declared to be invalid by the Member State in which they were issued.
In that regard, the Court has already stated that an A1 certificate, issued by the competent institution of a Member State, binds not only the institutions of the Member State in which the activity is carried out but also the courts of that Member State (judgment of 6 September 2018,
Alpenrind and Others
, C‑527/16, EU:C:2018:669, paragraph 47).
Article 5(2) to (4) of Regulation No 987/2009 lays down the detailed rules for the application of the procedure laid down in Article 76(6) of Regulation No 883/2004 for the purpose of resolving disputes between the institution of the Member State which receives the documents and supporting evidence referred to in Article 5(1) and the institution which issued those documents. More specifically, paragraphs (2) and (3) of Article 5  specify the steps which those institutions are to follow in the event of doubt as to the validity of those documents and supporting evidence or as to the accuracy of the facts on which the particulars contained therein are based, by requiring the issuing institution to reconsider the grounds for issuing those documents and, if necessary, to withdraw them. Article 5(4) provides that where no agreement is reached between the institutions concerned, the competent authorities may bring the matter before the Administrative Commission, which must endeavour to reconcile the points of view within six months of the date on which the matter was brought before it.
It is necessary to ascertain, as a first step, whether an A1 certificate, the effects of which were provisionally suspended, has no binding effect on the institutions and courts of the Member States during that period of provisional suspension.
In that regard, in the first place, it is apparent from the wording of Article 5(1) of Regulation No 987/2009 that only the withdrawal and declaration of invalidity of A1 certificates remove the binding effects of those certificates vis-à-vis the institutions and courts of the Member States.
Since the term ‘withdraw’ used by the EU legislature implies, in its legal sense, the disappearance of an act or its retroactive repeal on the basis of a decision of the administration which adopted it, the wording of Article 5(1) of Regulation No 987/2009 suggests that the decision of the issuing institution provisionally to suspend an A1 certificate does not entail the loss of its binding effects. That interpretation is supported by the fact that, apart from the case of withdrawal, the EU legislature provided for the loss of binding effects attaching to A1 certificates only in the event of a declaration of invalidity of those certificates, a declaration which is also in the nature of a definitive act equivalent to a cancellation of those certificates.
In the second place, the decision of the issuing institution, to which a request for the withdrawal of an A1 certificate was made by the institution of another Member State, to withdraw that certificate for the purposes of Article 5(1) of Regulation No 987/2009, must be taken in the context of the procedure of dialogue and reconciliation between institutions provided for in Article 76(6) of Regulation No 883/2004, the detailed rules for the application of which are set out in Article 5(2) to (4) of Regulation No 987/2009, where, following a reconsideration of the grounds for the issue of that certificate, the issuing institution considers, having regard to the actual situation of the worker concerned, that its social security system is not applicable to that worker.
It follows that only the decision to withdraw an A1 certificate adopted by the issuing institution in accordance with that procedure of dialogue and reconciliation and, therefore, following a reconsideration of the grounds for issuing that certificate and determining the social security scheme applicable to the worker concerned is capable of removing the binding effects of that certificate.
In that context, it must be recalled that, as the Court has already pointed out, the procedure of dialogue and reconciliation must be observed by the institutions of the Member States called on to apply Regulations No 883/2004 and No 987/2009 where there are disputes between the institutions of the Member States concerned regarding the validity or accuracy of an A1 certificate (see to that effect, as regards Regulation No 1408/71, judgment of 27 April 2017,
A-Rosa Flussschiff
, C‑620/15, EU:C:2017:309, paragraph 53).
To accept that the issuing institution may, even temporarily, remove the binding effects of an A1 certificate without having first reconsidered the grounds for its issue or determined which social security system is applicable to the worker concerned would be tantamount to disregarding both the detailed rules for the application of the procedure of dialogue and reconciliation and the purpose of that procedure.
In the third place, it is necessary to bear in mind the importance attached, in the context of Regulations No 883/2004 and No 987/2009, to the principles of the application of the legislation of a single Member State, of sincere cooperation and of legal certainty, which underlie all the Court’s case-law on the binding effect of E 101 certificates. Whilst the principle of legal certainty is referred to in recital 6 of Regulation No 987/2009, the principle of the affiliation of employees to a single social security system is set out in recital 15 and Article 11(1) of Regulation No 883/2004, whereas the importance of the principle of sincere cooperation is clear from both Article 76 of Regulation No 883/2004 and recital 2 and Article 20 of Regulation No 987/2009 (see, to that effect, judgment of 6 September 2018,
Alpenrind  and Others
, C‑527/16, EU:C:2018:669, paragraph 45).
In the situation referred to in paragraph 53 above, the principle of sincere cooperation on which the procedure of dialogue and reconciliation is based would be infringed as a result of failure to comply with that procedure.
Moreover, in such a situation, the lack of binding effects of the A1 certificate at issue would allow the institutions of the other Member States, and in particular the institutions of the Member State which had expressed doubts as to the accuracy and validity of that certificate, to make the worker concerned subject to their own social security system. Thus, an interpretation of Article 5 of Regulation No 987/2009 allowing the issuing institution provisionally to suspend an A1 certificate, by removing its binding effects for that provisional period, would be likely to increase the risk of duplication of social security systems, which would undermine the principle that employed persons are affiliated to a single social security system and the foreseeability of which system is applicable and, therefore, the principle of legal certainty (see to that effect, as regards Regulation No 1408/71, judgment of 2 April 2020,
CRPNPAC and Vueling Airlines
, C‑370/17 and C‑37/18, EU:C:2020:260, paragraph 70 and the case-law cited).
In that regard, it should be noted that that risk cannot be avoided by a declaration by the issuing institution of the A1 certificate, stating that, during the period of provisional cessation of the binding effects of that certificate, the worker concerned would remain subject to its social security system. Such a declaration cannot produce the effects of an A1 certificate, which include the binding effect on the institutions and courts of the Member States other than that of the institution which issued those certificates.
In the fourth and last place, in view of the complications which the possible duplication of applicable social security systems might entail, an interpretation of Article 5 of Regulation No 987/2009 as referred to in paragraph 56 above would also be liable to compromise the ultimate objective pursued both by A1 certificates and by the substantive rules laid down in Title II of that regulation, namely to facilitate freedom of movement for workers and freedom to provide services (see, by analogy, judgment of 6 February 2018,
Altun and Others
, C‑359/16, EU:C:2018:63, paragraph 35 and the case-law cited).
It follows from the foregoing that an A1 certificate, despite having been provisionally suspended by a decision of the issuing institution, does not cease to have binding effects during that period of provisional suspension, with the result that it continues to be binding upon the institutions and courts of the Member States.
It is therefore necessary to ascertain, as a second step, whether, in circumstances such as those set out in paragraph 39 of this judgment, a court of the Member State in which the work is carried out, before which criminal proceedings have been brought against persons suspected of having fraudulently obtained or used the A1 certificate at issue, may nevertheless find that there has been fraud and consequently disregard that certificate.
In that regard, it should be recalled that the Court has already held that the court or tribunal of the host Member State seised of an action in the context of legal proceedings brought against an employer for acts that may indicate that A1 certificates were fraudulently obtained or used may give a definitive ruling on the existence of such a fraud and disregard those certificates only if it finds, after, so far as is necessary, staying the judicial proceedings under national law, that, where the procedure of dialogue and reconciliation provided for in Article 76(6) of Regulation No 883/2004 has been initiated promptly, the institution that issued those certificates has failed to undertake a review of those certificates and to adopt a decision, within a reasonable time, on the evidence submitted to it by the competent institution of the host Member State, cancelling or withdrawing those certificates, as appropriate (see, by analogy, judgment of 2 April 2020,
CRPNPAC
and
Vueling Airlines
, C‑370/17 and C‑37/18, EU:C:2020:260, paragraph 80).
As the Court has already held, that procedure of dialogue and reconciliation constitutes an essential prerequisite for determining whether the conditions for the existence of a fraud are met and, therefore, to draw all useful conclusions as regards the validity of the A1 certificates at issue and the social security legislation applicable to the workers concerned. Thus, a court of the host Member State hearing criminal proceedings such as those  in the main proceedings cannot take no account of that procedure of dialogue and reconciliation (see, by analogy, judgment of 2 April 2020,
CRPNPAC
and
Vueling Airlines
, C‑370/17 and C‑37/18, EU:C:2020:260, paragraphs 71 and 73).
In the present case, although that procedure of dialogue and reconciliation was indeed initiated, the institution issuing the A1 certificates at issue in the main proceedings nevertheless, by failing correctly to apply the detailed rules for the application of that procedure, decided to defer the reconsideration of the validity of those certificates and the determination of the social security system applicable to the workers concerned until the conclusion of the criminal proceedings pending before the courts of the Member State in which the work is carried out.
In those circumstances, it appears that the issuing institution did not undertake a reconsideration of the certificates the fraudulent acquisition and use of which was at issue in the criminal proceedings referred to above and adopt a position, within a reasonable period, on the evidence in that respect submitted  by the competent institution of the host Member State.
Consequently, it must be possible for those matters to be relied on in the context of those criminal proceedings, in order to require the court of the Member State in which the work is carried out to disregard the certificates at issue (see judgment of 6 February 2018,
Altun and Others
, C‑359/16, EU:C:2018:63, paragraph 55).
In any event, it must be recalled that the persons who are alleged, in such judicial proceedings, to have used posted workers ostensibly covered by fraudulently obtained certificates must be given the opportunity to rebut the evidence on which those proceedings are based, with due regard to the safeguards associated with the right to a fair trial, before the national court decides, if appropriate, that the certificates should be disregarded and gives a ruling on the liability of those persons under the applicable national law (judgment of 6 February 2018,
Altun and Others
, C‑359/16, EU:C:2018:63, paragraph 56).
Accordingly, in circumstances such as those set out in paragraph 39 of the present judgment, a court of the Member State in which the work is carried out, seised in the context of criminal proceedings brought against persons suspected of having  fraudulently obtained or used an A1 certificate, may find that there has been fraud and consequently disregard that certificate, provided that the guarantees inherent in the right to a fair hearing which must be granted to those persons are respected.
Having regard to the foregoing considerations, the answer to the first question in Case C‑410/21 is that Article 5 of Regulation No 987/2009 must be interpreted as meaning that an A1 certificate issued by the competent institution of a Member State is binding upon the institutions and courts of the Member State in which the work is carried out, including where, following a request for reconsideration and withdrawal sent by the competent institution of that latter Member State to the issuing institution, that institution has declared that it has provisionally suspended the binding effects of that certificate until such time as it decides definitively on that request. However, in such circumstances, a court of the Member State in which the work is carried out, seised in the context of criminal proceedings brought against persons suspected of having fraudulently obtained or used the same A1 certificate, may find that there has been fraud and consequently disregard that certificate, for the purposes of those criminal proceedings, provided that, first, a reasonable period has elapsed without the issuing institution having reconsidered the grounds for issuing that certificate and having adopted a decision on the specific evidence submitted by the competent institution in the host Member State, which gave rise to the view that that certificate had been obtained or invoked fraudulently, as the case may be, by cancelling or withdrawing the certificate in question and, second, that the guarantees inherent in the right to a fair trial which must be afforded to those persons have been respected.

The second question in Case
C
‑
/21 and the first question in Case
C
‑
/21
By its second question in Case C‑410/21 and its first question in Case C‑661/21, which it is appropriate to examine together, the referring court asks, in essence, whether Article 13(1)(b)(i) of Regulation No 883/2004, read in the light of Article 3(1)(a) and Article 11(1) of Regulation No 1071/2009, and Article 4(1)(a) of Regulation No 1072/2009, must be interpreted as meaning that the fact that a company holds a Community licence for road transport issued by the competent authorities of a  Member State constitutes irrefutable evidence of that company’s registered office in that Member State for the purpose of determining, in accordance with Article 13(1)(b)(i) of Regulation No 883/2004, which national legislation on social security is applicable.
As is apparent from the requests for a preliminary ruling, the referring courts’ doubts arise from the fact that the issue of a Community licence for road transport  to an undertaking is subject, inter alia, to the requirement of having an effective and stable establishment, within the meaning of Article 3(1)(a) of Regulation No 1071/2009, in the Member State which issued the licence.
Such a requirement follows in particular from Article 4(1) of Regulation No 1072/2009.
It is therefore necessary to ascertain whether the concept of ‘registered office or place of business’, within the meaning of Article 13(1)(b)(i) of Regulation No 883/2004, corresponds to that of ‘an effective and stable establishment’, within the meaning of Article 3(1)(a) of Regulation No 1071/2009.
As regards, in the first place, the concept of ‘registered office or place of business’ within the meaning of Article 13(1)(b)(i) of Regulation No 883/2004, that provision provides that a person who normally pursues an activity as an employed person in two or more Member States and who does not pursue a substantial part of his or her activity in the Member State of residence is to be subject to the legislation of the Member State in which the registered office or place of business of the undertaking or employer is situated, if he or she is employed by one undertaking or employer.
Article 14(5a) of Regulation No 987/2009 states that, for the purposes of the application of Title II of Regulation No 883/2004, which includes Article 13(1)(b)(i), ‘registered office or place of business’ is to refer to the registered office or place of business where the essential decisions of the undertaking are adopted and where the functions of its central administration are carried out.
It follows that the element of connection of the ‘registered office or place of business’, referred to in Article 13(1)(b)(i) of Regulation No 883/2004 to designate the Member State whose social security legislation is applicable, is determined by the place from which an undertaking is in fact managed and organised.
As regards, in the second place, the concept of an ‘effective and stable establishment’ within the meaning of Article 3(1)(a) of Regulation No 1071/2009, as is apparent from Article 5 of that regulation, the fact that an undertaking has an ‘effective and stable establishment’ within the meaning of Article 3(1)(a) implies, in essence, first, that it has premises in which it holds the core business documents of the undertaking, second, that it has registered vehicles at its disposal and, thirdly, that it conducts effectively and continuously with the necessary administrative equipment its operations relating to those vehicles and with the appropriate technical equipment and facilities at an operating centre.
It follows that the concept of an ‘effective and stable establishment’, within the meaning of Article 3(1)(a) of Regulation No 1071/2009, refers essentially to the place where the undertaking’s core business documents are held and where its equipment, as well as its technical and administrative facilities, are located.
Therefore, the criteria for determining the place of establishment of a transport undertaking for the purposes of obtaining a Community licence for road transport are different from those used to determine the place of establishment of that undertaking for the purposes of Article 13(1)(b)(i) of Regulation No 883/2004.
Thus, while the effective and stable establishment, within the meaning of Article 3(1)(a) of Regulation No 1071/2009, and the place where the essential decisions of the undertaking are adopted or where the functions of its central administration are carried out may indeed be the same, that does not necessarily have to be the case.
Consequently, the concept of ‘registered office or place of business’, within the meaning of Article 13(1)(b)(i) of Regulation No 883/2004, does not correspond to that of ‘effective and stable establishment’, within the meaning of Article 3(1)(a) of Regulation No 1071/2009.
In those circumstances, the fact that a company holds a Community licence for road transport may be a factor to be taken into consideration when determining its registered office or place of business, for the purpose of determining the national social security legislation applicable in accordance with Article 13(1)(b)(i) of Regulation No 883/2004, but cannot automatically constitute proof of this, nor, a fortiori, irrefutable proof, nor can it be binding upon the authorities of the Member State in which the work is carried out.
Having regard to the foregoing considerations, the answer to the second question in Case C‑410/21 and the first question in Case C‑661/21, is that Article 13(1)(b)(i) of Regulation No 883/2004, read in the light of Article 3(1)(a) and Article 11(1) of Regulation No 1071/2009, and Article 4(1)(a) of Regulation No 1072/2009, must be interpreted as meaning that the fact that a company holds a Community licence for road transport issued by the competent authorities of a Member State does not constitute irrefutable proof that that company’s registered office is in that Member State for the purpose of determining, in accordance with Article 13(1)(b)(i) of Regulation No 883/2004, which national legislation on social security is applicable.

The second question referred in Case
C
‑
/21
In view of the answer given to the second question in Case C‑410/21 and the first question in Case C‑661/21, there is no need to answer the second question in the latter case.

Costs
Since these proceedings are, for the parties to the main proceedings, a step in the action pending before the referring court, the decision on costs is a matter for that court. Costs incurred in submitting observations to the Court, other than the costs of those parties, are not recoverable.
On those grounds, the Court (Second Chamber) hereby rules:
1.
Article 5 of Regulation (EC) No 987/2009 of the European Parliament and of the Council of 16 September 2009 laying down the procedure for implementing Regulation (EC) No 883/2004 on the coordination of social security systems, as amended by Regulation (EU) No 465/2012 of the European Parliament and of the Council of 22 May 2012,
must be interpreted as meaning that an A1 certificate issued by the competent institution of a Member State is binding upon the institutions and courts of the Member State in which the work is carried out, including where, following a request for reconsideration and withdrawal sent by the competent institution of that latter Member State to the issuing institution, that institution has declared that it has provisionally suspended the binding effects of that certificate until such time as it decides definitively on that request. However, in such circumstances, a court of the Member State in which the work is carried out, seised in the context of criminal proceedings brought against persons suspected of having fraudulently obtained or used the same A1 certificate, may find that there has been fraud and consequently disregard that certificate, for the purposes of those criminal proceedings, provided that, first, a reasonable period has elapsed without the issuing institution having reconsidered the grounds for issuing that certificate and having adopted a decision on the specific evidence submitted by the competent institution in the host Member State, which gave rise to the view that that certificate had been obtained or invoked fraudulently, as the case may be, by cancelling or withdrawing the certificate in question and, second, that the guarantees inherent in the right to a fair trial which must be afforded to those persons have been respected.
2.
Article 13(1)(b)(i) of Regulation (EC) No 883/2004 of the European Parliament and of the Council of 29 April 2004 on the coordination of social security systems, as amended by Regulation No 465/2012, read in the light of Article 3(1)(a) and Article 11(1) of Regulation (EC) No 1071/2009 of the European Parliament and of the Council of 21 October 2009 establishing common rules concerning the conditions to be complied with to pursue the occupation of road transport operator and repealing Council Directive 96/26/EC, and of Article 4(1)(a) of Regulation (EC) No 1072/2009 of the European Parliament and of the Council of 21 October 2009 establishing common rules for access to the international road haulage market,
must be interpreted as meaning that the fact that a company holds a Community licence for road transport issued by the competent authorities of a Member State does not constitute irrefutable proof that that company’s registered office is in that Member State for the purpose of determining, in accordance with Article 13(1)(b)(i) of Regulation No 883/2004, as amended by Regulation No 465/2012, which national legislation on social security is applicable.
[Signatures]
*
Language of the case: Dutch.