Opinion of the Advocate General — ECLI:EU:C:2023:512
Date: 2023-06-22
Language of the case: Polish
Subject matter: Social security for migrant workers;Free movement of workers
Procedure: Reference for a preliminary ruling
Origin: Poland

Summary C-422/22 – 1 
Case C-422/22 
Summary of the request for a preliminary ruling pursuant to Article 98(1) of 
the Rules of Procedure of the Court of Justice 
Date lodged: 
22 June 2022 
Referring court: 
Sąd Najwyższy (Poland) 
Date of the decision to refer: 
27 April 2022 
Appellant on a point of law: 
Zakład Ubezpieczeń Społecznych Oddział w Toruniu 
Respondent: 
TE 
  
Subject matter of the main proceedings 
An appeal on a point of law lodged by the Zakład Ubezpieczeń Społecznych 
Oddział w Toruniu (Social Insurance Institution, Toruń Branch, Poland (‘the 
SII’)) against the judgment of the Court of Appeal in Gdańsk of 5 February 2020. 
Subject matter and legal basis of the request 
Interpretation of European Union law: Article 4(3) TEU and regulations on the 
coordination of social security systems; arrangements with the competent 
institution of another Member State in the event of withdrawal of an A1 
certificate. 
Questions referred for a preliminary ruling 
1. Is the institution of a Member State which has issued an A1 form and which, 
of its own motion (without a request from the competent institution of the 
Member State concerned), intends to cancel/withdraw or invalidate the issued 
EN 
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form, obliged to make arrangements with the competent institution of another 
Member State in accordance with rules analogous to those set out in Articles 6 and 
16 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 …? 
2. Are the arrangements to be made even before the cancellation/withdrawal or 
invalidation of the issued form, or is the cancellation/withdrawal or invalidation 
provisional in nature (Article 16(2)) and will become final in the event that the 
Member State institution concerned does not raise any objection or present a 
different view on the matter? 
Provisions of European Union law relied on 
Articles 11 and 13 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 
Articles 5, 6, 15 and 16 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 
Provisions of national law relied on 
Article 83a(1) of the Ustawa z dnia 13 października 1998 r. o systemie 
ubezpieczeń społecznych (Law of 13 October 1998 on the Social Security 
System) 
‘A right or obligation established by a final decision [of the SII] shall be re-
determined at the request of the person concerned or ex officio if, after the 
decision has become final, new evidence is submitted or circumstances present 
prior to the decision are disclosed that affect that right or obligation.’ 
Article 47714a of the Kodeks Postępowania Cywilnego (Code of Civil Procedure, 
‘the CCP’) 
‘When setting aside a judgment and the decision of the pension authority 
preceding it, the court of second instance may refer the case directly back to the 
pension authority for reconsideration.’ 
Succinct presentation of the facts and procedure in the main proceedings 
1 TE is engaged in business activity, on which he pays taxes in Poland. On 
11 August 2016, TE signed an agreement with a company based in Warsaw, 
which is engaged in assembling facilities for the transfer of hazardous materials 
produced by cooperating companies. The subject of that agreement was the 
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provision of services usually performed by a second site manager. Those services 
were to be provided in France from 22 August 2016 until the end of the project. 
2 An A1 certificate certifying the application of Polish legislation was issued with 
respect to TE for the period from 22 August 2016 until 21 August 2017. On 
1 December 2017, the SII (which is a pension authority within the meaning of 
Article 47714a of the CCP) issued a decision in which, acting pursuant to 
Article 83a(1) of the Law on the Social Security System, read in conjunction with 
Article 5(1) of Regulation No 987/2009 and Article 11(3)(a) of Regulation 
No 883/2004, it: (1) withdrew the A1 certificate confirming that Polish legislation 
was applicable to TE from 22 August 2016 until 21 August 2017; (2) found that 
TE was not subject to Polish legislation during the period from 22 August 2016 
until 21 August 2017 (‘the contested decision’). In doing so, the SII did not follow 
the procedure stipulated in Article 16 of Regulation No 987/2009, finding that 
Article 13, rather than Article 11 of Regulation No 883/2004, applied in TE’s 
case. 
3 TE appealed the SII’s decision to the Sąd Okręgowy (Regional Court) in Toruń, 
Poland. The court amended the contested decision, finding that TE was subject to 
Polish legislation from 22 August 2016 until 21 August 2017, and upheld the A1 
certificate. The court held that Article 13(2) of Regulation No 883/2004, which 
applies to self-employment in two or more Member States, was applicable in TE’s 
case. According to the court, the SII incorrectly invoked Article 11(1) of the 
regulation by considering that TE performed work exclusively in one Member 
State. In the view of the Regional Court, the SII failed to exhaust the coordination 
procedure set out in Articles 6, 15 and 16 of Regulation No 987/2009. In the 
course of the proceedings, the Regional Court repeatedly asked the SII to take a 
position in that regard and to consider coordination with the competent French 
institution. The court even obliged the SII to initiate and carry out a dispute 
resolution procedure concerning the determination of applicable legislation in 
accordance with the provisions of the implementing regulation; however, the SII 
did not recognise any basis for making arrangements with the foreign insurance 
institution. On the other hand, it was impossible to remedy that deficiency in court 
proceedings, as the court does not have the required legal instruments. The 
Regional Court was cognisant of the need to prevent a situation in which the 
insured would not be subject to any social security system as a result of the SII’s 
actions. In view of the SII’s failure to initiate the coordination procedure, and 
having in mind the insured’s interests, the Regional Court found that TE was 
subject to Polish legislation from 22 August 2016 until 21 August 2017. 
4 The SII lodged an appeal against the Regional Court’s judgment, which the Sąd 
Apelacyjny (Court of Appeal, Poland) dismissed. In its reasoning, the Court of 
Appeal confirmed the Regional Court’s findings of fact and its legal assessment of 
those findings. The Court of Appeal stressed that it did not deny the SII’s right to 
conduct a review after the first decision had been issued, and to change, as a result 
of that review, its assessment of the insured’s situation, as well as to issue a 
decision determining that the insured was not subject to Polish legislation. 
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However, contrary to the SII’s position, the Court of Appeal held that the 
application of the procedure stipulated in Article 16 of Regulation No 987/2009 
was mandatory, and thus the issuance of that decision required prior exhaustion of 
the consultation procedure between the competent institutions in Poland and 
France. The Court of Appeal found that there was no basis for withdrawing the A1 
certificate confirming that Polish social security legislation applied to TE from 
22 August 2016 until 21 August 2017, since during that period he normally 
pursued activities as a self-employed person in Poland and France, and Poland 
was invariably the centre of interest of his activities from the time those activities 
were registered (Article 13(2)(b) of Regulation No 883/2004). 
5 The SII lodged an appeal on a point of law with the Sąd Najwyższy (Supreme 
Court, Poland) against the judgment of the Court of Appeal. 
Essential arguments of the parties in the main proceedings 
6 In its appeal on a point of law, the SII alleged an infringement of substantive law, 
namely Article 13(2)(b) of Regulation No 883/2004, read in conjunction with 
Article 14(5b), Article 14(6), Article 14(8) and Article 14(9) of Regulation 
No 987/2009, consisting in the application of those provisions despite the SII not 
having carried out the procedure referred to in Article 16(2) to (4) of Regulation 
No 987/2009, and an infringement of the rules of procedure by issuing a judgment 
on the merits in a situation where there were grounds for setting aside the 
judgment of the court of first instance and the decision of the SII that preceded it, 
and for referring the case back to the SII. 
7 In the grounds of its appeal on a point of law, the SII took the position that the 
coordination procedure must in each case precede the final determination of the 
applicable legislation, and the provisions of the regulation do not provide for any 
exceptions in that regard. In view of this, it is unjustified for the court of second 
instance to assume that since, on the basis of the evidence taken in the course of 
the proceedings, it can be established that Polish legislation would be applicable 
to TE, it is unnecessary to make arrangements [with the foreign insurance 
institution] in the case. Therefore, there was no basis for ruling on the merits in a 
case which, owing to the decision being legally flawed, was not suitable for such a 
ruling at all. Thus, the contested judgment was delivered in violation of the rules 
of procedure, which had a significant impact on the outcome of the case. Indeed, 
if the Court of Appeal had applied the rules of procedure in question, 
Article 13(2)(b) of Regulation No 883/2004 would not have been applied and no 
legislation applicable to TE would have been determined, and the case would have 
been referred back to the SII. 
Succinct presentation of the reasoning in the request for a preliminary ruling 
8 The resolution of the Supreme Court’s doubts presented in the questions referred 
is important for the outcome of the case, since there is uncertainty about how the 
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principle of sincere cooperation under Article 4(3) TEU is to be implemented in a 
situation where a Member State withdraws an A1 certificate it has issued, having 
independently come to the conclusion that the information contained therein does 
not comply with the applicable legislation determined in accordance with the 
relevant provisions of Regulations No 883/2004 and No 987/2009. 
9 Those doubts boil down to the question of whether the institution that withdraws 
the A1 certificate of its own motion, without a request from another Member 
State, is obliged to make arrangements concerning insurance coverage with the 
competent institution of another Member State in accordance with rules analogous 
to those set out in Articles 6 and 16 of Regulation No 987/2009, and to determine 
the point in time at which such arrangements should be made: (1) before the 
withdrawal of the A1 certificate; or (2) after its withdrawal. That choice should be 
made while ensuring effective protection of the insured’s interests, such that the 
withdrawal of the A1 certificate does not result in a situation where the insured is 
not covered by the legislation of any Member State. 
10 Accepting that arrangements must be made between Member States with respect 
to the withdrawal of the A1 certificate and recognising that they need to be made 
even prior to the withdrawal would mean that the SII decision was flawed, which 
pursuant to national legislation would result in a formal ruling amending the 
judgment of the Court of Appeal, and this in turn would result in the setting aside 
of the judgment of the Regional Court and of the contested decision that preceded 
it, and in the case being referred directly back to the SII in order for the SII to 
follow the coordination procedure already at the stage when the A1 certificate is 
withdrawn. 
11 On the other hand, recognising that arrangements are necessary, but that they can 
be made after the withdrawal of the certificate, would mean that the contested 
decision is correct in formal terms and that the contested judgment needs to be 
reviewed in order to determine whether there were grounds for withdrawing the 
A1 certificate confirming that during the period from 22 August 2016 until 
21 August 2017, Polish social security legislation was applicable to TE, and 
therefore whether during the period concerned TE normally pursued activities as a 
self-employed person in Poland and France (where he performed a significant part 
of his work), and whether Poland was the centre of interest of his activities 
(Article 13(2)(b) of Regulation No 883/2004). 
12 Where an A1 form certifies that the insured is covered by social security insurance 
in the Member State of the place of his or her employment, it is possible to 
determine the legislation applicable to the insured. Only after the A1 form has 
been withdrawn or invalidated, and the grounds for issuing it have been 
reconsidered, can the legislation of the Member State of his or her residence be 
determined to be applicable. The withdrawal of an A1 certificate which was 
issued in circumstances where it was not appropriate is possible at any time if it 
turns out that the conditions for its issuance – resulting from EU regulations – 
have not been met (judgments of the Court of Justice, Alpenrind; Herbosch Kiere 
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NV; A-Rosa Flussschiff GmbH; Format Urządzenia i Montaże Przemysłowe; as 
well as the order in Belu Dienstleistung and Nikless). 
13 Certainly, the provisions of coordination regulations suggest that the institution 
which withdraws the A1 certificate is obliged to inform the competent institution 
of the place of employment that such a decision has been issued. That information 
should, in turn, result in the person in question being covered by the social 
security system of the ‘competent’ Member State. The basis for such an obligation 
being imposed on competent institutions is Article 2(2) of Regulation 
No 987/2009. To that end, it would be sufficient to interpret the provision 
concerned as meaning that the findings justifying the withdrawal of the A1 
certificate are ‘data necessary for establishing and determining the rights and 
obligations of persons to whom the basic Regulation applies’. It could also be 
considered whether Article 2(2) of Regulation No 987/2009 should be interpreted 
as meaning that the institution intending to withdraw the A1 certificate should 
inform the institution of another Member State already of its intention to withdraw 
the certificate. As a result, the target Member State’s competent institution would 
have the information necessary for it to take steps to cover the person in question 
by the social security legislation of that Member State. 
14 However, under both interpretations of Article 2(2) of Regulation No 987/2009, 
failure to comply with the information obligation would not mean that the 
decision of the competent institution withdrawing the A1 certificate was defective, 
since that obligation binds the competent institutions outside the scope of 
certificate withdrawal proceedings. 
15 Therefore, the mere notification of the withdrawal or intention to withdraw the A1 
certificate does not have an effect relevant to compliance with the principle 
referred to in Article 11(1) of Regulation 883/2004 and to safeguarding the 
employee’s interests, since it does not guarantee that the person in question will 
actually be covered by the social security system that is ‘appropriate’ under EU 
coordination rules. Therefore, it must be considered whether, where the A1 
certificate is withdrawn, the withdrawing institution should be obliged to agree 
coverage with the competent institution of another Member State in accordance 
with rules analogous to those set out in Articles 6 and 16 of Regulation 
No 987/2009. 
16 From the point of view of employees covered by the A1 certificate, its 
withdrawal – in the absence of cooperation between the withdrawing institution 
and the competent institution – results in a state of uncertainty as to the existence 
of insurance, the scope of coverage and the institution competent to provide it. 
That uncertainty undermines the effectiveness of Union laws on social security 
coordination, and thus the effectiveness of the freedom of movement of workers. 
Indeed, where the competent institution of a Member State unilaterally withdraws 
the A1 certificate, there is a serious risk that: (a) the person in question would be 
excluded from the social security system of the Member State of the institution 
that withdrew the certificate; (b) no legislation would be applicable to that person 
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until he or she was covered by the social security system of another Member 
State; (3) the institution of the Member State of that person’s place of employment 
could not cover him or her under its social security system. 
17 It should be emphasised that Article 5(2) to (4) of Regulation No 987/2009, which 
stipulates the circumstances in which the institution issuing the A1 certificate is 
obliged to reconsider the grounds for issuing it and its possible withdrawal, does 
not explicitly stipulate – unlike the rules for determining the applicable legislation 
under Article 6 and Article 16 of Regulation No 987/2009 – the detailed 
procedure for cooperation between the competent institutions of different Member 
States. Only Article 5(4) of Regulation No 987/2009 refers to a situation in which 
‘no agreement is reached between the institutions concerned’ on, among other 
things, the withdrawal of the A1 certificate. Then the matter may be brought 
before the Administrative Commission. The wording of Article 5(4) of Regulation 
No 987/2009 therefore suggests that when considering the grounds for 
withdrawing the A1 certificate, the institution that issued the certificate should 
cooperate with the competent institution of the place of employment, which also 
implies agreeing a position on which legislation will apply to the person in 
question if the A1 certificate is withdrawn. 
18 Such an interpretation of Article 5 of Regulation No 987/2009 is supported by the 
assumption that the provisions on EU coordination should be interpreted in such a 
manner that the withdrawal of the A1 certificate does not result in an infringement 
of the principle that a person shall be subject to the legislation of one Member 
State. That principle entails an important directive for the institutions of the 
competent Member States and review bodies: their procedures must not result in a 
person being subject to more than one body of legislation, nor must they exclude 
that person from being subject to any legislation. 
19 The procedure governing the rules of dialogue and conciliation, which is 
contained in Decision No A1, does not provide an answer as to how to proceed 
before a decision is issued to withdraw the A1 certificate. Recital 4 of Decision 
No A1 invokes the principle of sincere cooperation, as also laid down in 
Article 4(3) TEU, which requires that institutions conduct a proper assessment of 
the facts relevant for the application of the Regulations. It is also pointed out that 
‘where there is doubt about the validity of a document or about the correctness of 
supporting evidence …, it is in the interest of the persons covered by Regulation 
(EC) No 883/2004 that institutions or authorities of the Member States concerned 
reach an agreement within a reasonable period of time’. Article 4(3) TEU has also 
been referred to in judgments of the Court of Justice on coordination in order to 
clarify certain obligations of the competent institutions in connection with the 
withdrawal of A1 certificates (Altun, C-359/16, paragraphs 35-40, and Alpenrind, 
C-527/16, paragraph 47). In the view of the Supreme Court, it follows from the 
above that more specific obligations of the institutions competent for the 
coordination of social security systems can be derived from Article 4(3) TEU, 
which will serve the purposes of Article 45 TFEU.