1 By judgments of 4 May 1987, which were received at the Court Registry on 15 May 1987, the Belgian Hof van Cassatie ( Third Chamber ) referred to the Court for a preliminary ruling under Article 177 of the Treaty two preliminary questions relating to the interpretation of Articles 7 and 52 of the Treaty .
2 Those questions arose in the course of proceedings between the Rijksinstituut voor de Sociale Verzekering der Zelfstandigen ( National Social Insurance Institute for Self-Employed Persons, hereinafter referred to as 'RSVZ' ) and Messrs Wolf and Dorchain and the companies of which they have respectively been a director since 1973 and managing shareholder since 1978, relating to the payment of contributions to the Belgian social security scheme for self-employed persons in respect of those activities .
3 Mr Wolf and Mr Dorchain have been employed in the Federal Republic of Germany since 1963 and 1978 respectively . They base their request for exemption from the payment of the contributions in question on Article 12 ( 2 ) of Royal Decree No 38 establishing the social security scheme for self-employed persons ( Belgisch Staatsblad of 29 July 1967 ). Under that provision a self-employed person is not liable to pay contributions if his income earned in that capacity does not reach a certain threshold and if, in addition to that activity, he habitually pursues, by way of principal occupation, another occupational activity .
4 RSVZ, however, claims that the "other occupational activity" mentioned in Article 12 ( 2 ), as further defined by Article 35 of the Royal Decree of 19 December 1967 ( Belgisch Staatsblad of 29 December 1967 ), amended by the Royal Decree of 15 July 1970, relates solely to employment covered by a Belgian social security scheme .
5 The Hof van Cassatie considered that the arguments thus submitted by the parties to the dispute raised a question of interpretation of Community law; it therefore stayed the proceedings and referred the following questions to the Court of Justice for a preliminary ruling : "With reference to the periods from 1973 to 1977 ( Case 154/87 ) and from 1978 to 1981 ( Case 155/87 ) respectively, must Article 52 of the EEC Treaty, whether or not in conjunction with Article 7, be interpreted as meaning that a Member State, namely Belgium, could impose, under Article 35 ( 1 ) of the Royal Decree of 19 December 1967, a greater liability to pay contributions under its social security scheme for self-employed persons on persons who are nationals of another Member State or persons who pursue an occupation or secondary occupation as self-employed persons within its territory, but who pursue an occupation or principal occupation as an employed person in their Member State of origin or another Member State and hence are not subject to a Belgian pension scheme, than on its own nationals or persons who are subject to a Belgian pension scheme as employed persons? Or with reference to the said periods must the abovementioned provisions of the EEC Treaty be interpreted as meaning that the said national of the other Member State or person who is not subject to a Belgian pension scheme as an employee must, for the purposes of determinining his liability to pay contributions under the social security scheme for self-employed persons, be treated by the legislation of the Member State within whose territory he pursues an activity as a self-employed person as if he were employed within the territory of that State?"
6 Reference is made to the Report for the Hearing for a more detailed account of the facts of the main proceedings, the provisions of national and Community law in issue and the observations submitted to the Court, which are mentioned or discussed hereinafter only in so far as is necessary for the reasoning of the Court .
7 A Community scheme for self-employed persons was introduced by Council Regulation No 1390/81 of 12 May 1981 extending to self-employed persons and members of their families Council Regulation No 1408/71 ( Official Journal 1981, L 143, p . 1 ). According to Article 2 of that regulation no rights are acquired thereunder in respect of a period prior to the date of its entry into force . It appears from Article 4 that the regulation entered into force only on 1 July 1982, that is to say, after the periods relevant to the main proceedings ( 1973 to 1977 in Mr Wolf' s case; 1978 to 1981 in Mr Dorchain' s case ). The regulation is therefore not applicable to those disputes, and the questions put by the national court is correct in referring only to the relevant Treaty provisions .
8 Article 7 of the Treaty forbids any discrimination on grounds of nationality within the scope of application of the Treaty .
9 It appears, however, from the documents before the Court that the national legislation which gave rise to the main proceedings is applicable without distinction to all self-employed persons working in Belgium and does not discriminate according to the nationality of those persons . Although it is true that self-employed persons whose principal occupation is employment in a Member State other than Belgium are thereby placed at a disadvantage, nothing has been submitted to the Court to show that the persons disadvantaged are exclusively or mainly foreign nationals . Nor, therefore can the national legislation at issue be considered to result in indirect discrimination on grounds of nationality . Consequently Article 7 of the Treaty may be dismissed from consideration .
10 The first paragraph of Article 52 of the Treaty requires the abolition of all restrictions on the freedom of establishment of nationals of a Member State in the territory of another Member State . It is settled law that that is a directly applicable rule of Community law . Member States were therefore under the obligation to observe that rule even though, in the absence of Community legislation on social security for self-employed persons, they retained legislative jurisdiction in this field .
11 As the Court has held ( in particular in the judgment of 12 July 1984 in Case 107/83 Ordre des avocats v Klopp (( 1984 )) ECR 2971, and the judgment of 28 January 1986 in Case 270/83 Commission v France (( 1986 )) ECR 273 ) freedom of establishment is not confined to the right to create a single establishment within the Community, but entails the right to set up and maintain, subject to observance of the relevant professional rules of conduct, more than one place of work within the territory of the Community .
12 That is equally true in respect of a person who is employed in one Member State and wishes, in addition, to work in another Member State in a self-employed capacity .
13 The provisions of the Treaty relating to the free movement of persons are thus intended to facilitate the pursuit by Community citizens of occupational activities of all kinds throughout the Community, and preclude national legislation which might place Community citizens at a disadvantage when they wish to extend their activities beyond the territory of a single Member State .
14 The legislation of a Member State which exempts persons whose principal occupation is employment in that Member State from the obligation to pay contributions to the scheme for self-employed persons but withholds such exemption from persons whose principal occupation is employment in another Member State has the effect of placing at a disadvantage the pursuit of occupational activities outside the territory of that Member State . Articles 48 and 52 of the Treaty therefore preclude such legislation .
15 Finally, it should be noted that the contested national provision affords no additional social protection to the persons concerned, who are affiliated to the social security and pension scheme of the Member State in which they pursue their principal employment . It follows that the impediment to the pursuit of occupational activities in more than one Member State may not in any event be justified on that basis .
16 The reply to be given to the questions of the national court must therefore be that Articles 48 and 52 of the Treaty must be interpreted as meaning that a Member State may not refuse to exempt self-employed persons working within its territory from the contributions provided for under the national legislation on social security for self-employed persons on the ground that the employment which is capable of giving entitlement to such exemption is pursued within the territory of another Member State .