KN v Raad van bestuur van de Sociale verzekeringsbank (C-203/24)

Contents

Judgment of the Court (Sixth Chamber)4 September 2025^note(Reference for a preliminary ruling — Social security — Migrant workers — Legislation applicable — Regulation (EC) No 883/2004 — Article 13(1) — Regulation (EC) No 987/2009 — Article 14(8) and (10) — Worker normally employed in several Member States — Pursuit of less than 25% of the activity in the Member State of residence — Concept of ‘substantial part of the activity’ — Connecting factors relating to working time and/or remuneration — Consideration of other circumstances — Length of the assessment period — Discretion of the competent institutions)In Case C‑203/24 [Hakamp],^noteREQUEST for a preliminary ruling under Article 267 TFEU from the Hoge Raad der Nederlanden (Supreme Court of the Netherlands), made by decision of 15 March 2024, received at the Court on 15 March 2024, in the proceedingsKNvRaad van bestuur van de Sociale verzekeringsbank,THE COURT (Sixth Chamber),composed of A. Kumin, President of the Chamber, F. Biltgen (Rapporteur), President of the First Chamber, and I. Ziemele, Judge,Advocate General: A. Rantos,Registrar: A. Calot Escobar,having regard to the written procedure,after considering the observations submitted on behalf of:– KN, by M.J. van Dam, advocaat,– the Netherlands Government, by M.K. Bulterman and M.H.S. Gijzen, acting as Agents,– the Czech Government, by J. Benešová and M. Smolek and J. Vláčil, acting as Agents,– the French Government, by R. Bénard and M. Guiresse, acting as Agents,– the Government of the Principality of Liechtenstein, by A. Entner-Koch and R. Schobel, acting as Agents,– the European Commission, by B.‑R. Killmann and F. van Schaik, acting as Agents,having decided, after hearing the Advocate General, to proceed to judgment without an Opinion,gives the following

Judgment

1This request for a preliminary ruling concerns the interpretation of Article 13(1) 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’), and of Article 14(8) 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 (OJ 2009 L 284, p. 1), as amended by Regulation No 465/2012 (‘Regulation No 987/2009’).

2The request has been made in proceedings between KN, an employee, and the Raad van Bestuur van de Sociale Verzekeringsbank (Management Board of the Social Insurance Bank, Netherlands) (‘the SVB’) concerning the provisional determination of the social security legislation applicable to him.

Legal context

European Union law

Regulation No 883/2004

3Recitals 1, 3 and 45 of Regulation No 883/2004 are worded as follows:(1) The rules for coordination of national social security systems fall within the framework of free movement of persons and should contribute towards improving their standard of living and conditions of employment.…(3) 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 has been amended and updated on numerous occasions in order to take into account not only developments at Community level, including judgments of the Court of Justice, but also changes in legislation at national level. Such factors have played their part in making the Community coordination rules complex and lengthy. Replacing, while modernising and simplifying, these rules is therefore essential to achieve the aim of the free movement of persons.…(45) Since the objective of the proposed action, namely the coordination measures to guarantee that the right to free movement of persons can be exercised effectively, cannot be sufficiently achieved by the Member States and can therefore, by reason of the scale and effects of that action, be better achieved at Community level, …’

4Article 11 of that regulation provides:1. 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.…’

5Article 13 of that regulation, entitled ‘Pursuit of activities in two or more Member States’, provides, in paragraph 1:‘A person who normally pursues an activity as an employed person in two or more Member States shall be subject:(a) to the legislation of the Member State of residence if he/she pursues a substantial part of his/her activity in that Member State; or(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 ……’

Regulation No 987/2009

6Recital 1 of Regulation No 987/2009 is worded as follows:‘Regulation [No 883/2004] modernises the rules on the coordination of Member States’ social security systems, specifying the measures and procedures for implementing them and simplifying them for all the players involved. Implementing rules should be laid down.’

7Article 14 of that regulation, entitled ‘Details relating to Articles 12 and 13 of [Regulation No 883/2004]’, provides, in paragraph 8:‘For the purposes of the application of Article 13(1) and (2) of [Regulation No 883/2004], a “substantial part of employed or self-employed activity” pursued in a Member State shall mean a quantitatively substantial part of all the activities of the employed or self-employed person pursued there, without this necessarily being the major part of those activities.To determine whether a substantial part of the activities is pursued in a Member State, the following indicative criteria shall be taken into account:(a) in the case of an employed activity, the working time and/or the remuneration; and(b) in the case of a self-employed activity, the turnover, working time, number of services rendered and/or income.In the framework of an overall assessment, a share of less than 25% in respect of the criteria mentioned above shall be an indicator that a substantial part of the activities is not being pursued in the relevant Member State.’

8Article 14(10) of that regulation provides:‘For the determination of the applicable legislation under paragraphs 8 and 9, the institutions concerned shall take into account the situation projected for the following 12 calendar months.’

9Article 16 of that regulation, which deals with the ‘Procedure for the application of Article 13 of [Regulation No 883/2004]’, provides, in paragraphs 1 and 2:1. A person who pursues activities in two or more Member States shall inform the institution designated by the competent authority of the Member State of residence thereof.2. The designated institution of the place of residence shall without delay determine the legislation applicable to the person concerned, having regard to Article 13 of [Regulation No 883/2004] and Article 14 of [Regulation No 987/2009]. That initial determination shall be provisional. The institution shall inform the designated institutions of each Member State in which an activity is pursued of its provisional determination.’

Decisions of the European Economic Area (EEA) Joint Committee

10Annex VI (Social security) to the Agreement on the European Economic Area of 2 May 1992 (OJ 1994 L 1, p. 3) includes, pursuant to the Decision of the EEA Joint Committee No 76/2011 of 1 July 2011 amending Annex VI (Social security) and Protocol 37 to the EEA Agreement (OJ 2011 L 262, p. 33), which entered into force on 1 June 2012, Regulation No 883/2004 and Regulation No 987/2009 as ‘acts referred to’. Those regulations have applied to Liechtenstein since 1 June 2012.

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

11In 2016, KN was residing in the Netherlands. Between 4 February and 31 December 2016 (‘the period at issue’), he worked as a boatman on an inland waterway vessel (‘the vessel’), registered in the Netherlands and owned and operated by a shipping company registered and established in the Netherlands. KN worked in Belgium, Germany and the Netherlands. According to the logbook of the vessel, the vessel sailed in the Netherlands for approximately 22% of its total sailing time in 2016. During the period at issue, KN appeared on the staff register of an employer established in Liechtenstein.

12It is also apparent from that logbook that, in 2013 and 2014, the vessel had already sailed in the Netherlands for 22% and 24% of its total sailing time, respectively. During that period, however, KN did not work either for the employer established in Liechtenstein or on the vessel.

13By letter of 25 July 2017, the competent institution for the Principality of Liechtenstein requested, on the basis of Article 6 of Regulation No 987/2009, the SVB to determine provisionally the legislation applicable to KN for the period at issue.

14By decision of 8 November 2019, the SVB considered that Netherlands legislation was the legislation applicable for the period at issue and issued a certificate (A1 certificate) confirming that the Netherlands social security system applied for that period.

15KN lodged an objection, which was rejected by the SVB by decision of 6 March 2020 on the ground that, during the period at issue, KN had pursued a substantial part of his employed activities in the Netherlands. In order to make that finding, the SVB took into account not only the sailing time of the vessel on which KN worked, as set out in the logbook, but also the fact that he resided in the Netherlands, that the vessel was registered there and that the owner and operator of that vessel were established there.

16After his action against that decision of the SVB was dismissed by the rechtbank Midden-Nederland (District Court, Central Netherlands, Netherlands), KN brought an appeal before the Centrale Raad van Beroep (Higher Social Security and Civil Service Court, Netherlands), producing documents allegedly showing that his working time in the Netherlands was merely 18.5% of his total working time during the period at issue.

17By judgment of 19 May 2022, the Centrale Raad van Beroep (Higher Social Security and Civil Service Court) dismissed that appeal, holding that Netherlands social security legislation was indeed applicable for the period at issue. According to that court, a worker who pursues less than 25% of his or her employed activities in the Member State of residence could nevertheless be deemed to pursue a substantial part of that activity in that State, if there are sufficient other indications to that effect.

18The Centrale Raad van Beroep (Higher Social Security and Civil Service Court) held that the SVB had shown to the requisite standard that KN had carried out a substantial part of his employed activities in the Member State of residence, taking into account, in that regard, that the vessel on which he had worked also sailed in 2013 and 2014 in the Netherlands during 22% and 24% of its total sailing time, respectively, that the person concerned resided in the Netherlands, that the vessel was registered there and that both the owner and the operator of the vessel were established there.

19KN brought an appeal on a point of law against the decision of the Centrale Raad van Beroep (Higher Social Security and Civil Service Court) before the Hoge Raad der Nederlanden (Supreme Court of the Netherlands), the referring court. He submits that the Centrale Raad van Beroep (Higher Social Security and Civil Service Court), by taking into account irrelevant circumstances in order to assess where he pursued the substantial part of his employed activities, applied incorrectly Article 13 of Regulation No 883/2004 and Article 14(8) of Regulation No 987/2009. Furthermore, according to KN, that court was wrong not to take into account the fact that the employer is established in Liechtenstein and that KN boarded and disembarked from the vessel in Belgium, not in the Netherlands.

20In that context, the referring court raises several questions.

21In the first place, that court seeks to ascertain what circumstances may be relevant for a finding that workers who complete less than 25% of their working time in the Member State of residence still pursue a substantial part of their employed activities there.

22According to the referring court, it follows indisputably from the use, in the Dutch-language version of Article 14(8) of Regulation No 987/2009, of the terms ‘mede’ (‘also’) and ‘indicatieve criteria’ (‘indicative criteria’) and of the noun ‘indicatie’ (‘indicator’) that, if the working time and/or remuneration in the Member State of residence represent less than 25% of those criteria envisaged for all the worker’s activities in the various Member States, there is a possibility of taking into account other circumstances in an overall assessment of that worker’s situation.

23However, the referring court submits that not only does Article 14(8) of Regulation No 987/2009 not mention what those other relevant circumstances are, but it is also difficult to know what importance must be attached to the last subparagraph of paragraph 8, according to which a share of less than 25% of the connecting factors referred to in that paragraph is an indication that a substantial part of the activities is not pursued in the Member State of residence.

24The wording of Article 13(1)(a) of Regulation No 883/2004 makes it possible to assert that the concept of ‘substantial part’ must relate to the employed activities of the person concerned. Article 14(8) of Regulation No 987/2009 makes it clear that this must be part of the activities which, from a quantitative point of view, are significant. Thus, the referring court leans towards the finding that the other circumstances must have a direct link with the pursuit of the activities, give an indication as to the place where the activities are pursued and, as regards the importance which may be attached to the activities pursued in the Member State of residence in relation to all the activities of the person concerned, give rise to quantitative conclusions.

25The referring court considers, secondly, that it is necessary to exclude from the various circumstances to be taken into consideration the place where the vessel is registered, the place where the owner and operator of the vessel are established, the place where the worker boards and/or disembarks from the vessel, or even information on the sailing time or place in the years during which the employee was not in the service of his Liechtenstein employer. Furthermore, the place of residence of the worker cannot, according to the referring court, constitute a relevant indication, since Article 13(1) of Regulation No 883/2004 corresponds precisely to the situation in which a worker pursues part of his or her activities in the Member State of residence. Similarly, the place where the employer is established does not have any connection with the pursuit of activities in that State.

26In the third place, as regards the period to be taken into consideration in order to assess whether an employee pursues a substantial part of his or her activity in the Member State of residence, the referring court is uncertain whether it must be limited to the period covered by the A1 certificate or whether it may be extended, if necessary, in order to correspond to a calendar year. Article 14(10) of Regulation No 987/2009 provides for account to be taken of the situation projected for the following 12 calendar months without specifying, however, from when that period is calculated, either from the relevant day onwards or from the end of a specified period.

27Regulation No 987/2009 contains no provision on taking into account a period prior to that in question. According to the Practical guide on the applicable legislation in the European Union (EU), the European Economic Area (EEA) and in Switzerland, prepared and agreed by the Administrative Commission for the Coordination of Social Security Systems and published in December 2013 (‘the Practical guide’), previous arrangements for the pursuit of activities could also constitute a reliable indicator of the future behaviour of the worker concerned.

28In the fourth place, the referring court raises the question of the degree of discretion enjoyed by the competent institution in issuing an A1 certificate in order to determine whether a worker pursues a substantial part of his or her activities in the Member State of residence.

29In those circumstances, the Hoge Raad der Nederlanden (Supreme Court of the Netherlands) decided to stay the proceedings and to refer the following questions to the Court of Justice for a preliminary ruling:(1) What circumstances or types of circumstances are appropriate for assessing on the basis of Article 14(8) of [Regulation No 987/2009] the question whether a person who normally pursues an activity as an employed person in two or more Member States pursues a substantial part of his activities in the State of residence in a case in which it is established that he performs activities there for 22[%] of his working time? Is it required in that respect that: (i) a circumstance be directly linked to the pursuit of activities, (ii) a circumstance contain an indication as to the place where the activities are performed, and (iii) quantitative conclusions can be drawn from the circumstance as to the weight that can be attributed to the activities that are performed in the State of residence as compared with the total of all the activities of the person concerned?(2) Must or can this assessment, in view of the answer to question 1, take into account: (i) the residence of the employee, (ii) the place of registration of the barge on which the employee performs his activities, (iii) the place of establishment of the owner and operator of the barge, (iv) the place where the vessel sailed during other periods in which the employee was not working on it and was not yet in the service of the employer, (v) the place of establishment of the employer, and (vi) the place where the employee boards and disembarks the vessel?(3) Over which period must it be assessed whether an employee pursues a substantial part of his activities in his State of residence?(4) Does the competent body of a Member State, in determining the legislation applicable, have discretion which the courts must in principle respect with regard to the concept of “substantial part of his activity” in Article 13(1) of [Regulation No 883/2004] and, if so, how far does that discretion extend?’

The questions referred for a preliminary ruling

The first and second questions

30By its first and second questions, which it is appropriate to examine together, the referring court asks, in essence, whether Article 14(8) of Regulation No 987/2009 must be interpreted as meaning that, in order to assess whether a person who normally pursues an activity as an employed person in two or more Member States carries out a substantial part of that activity in the Member State of residence, it is open to the competent institution to take into account circumstances other than the time worked and/or the remuneration obtained in that State.

31It is apparent from the wording of Article 14(8) of Regulation No 987/2009 that a ‘substantial part of employed or self-employed activity’ pursued in a Member State means that a quantitatively substantial part of all the activities of the employed or self-employed person is pursued there, without this necessarily being the major part of those activities. To determine whether a substantial part of the activities is pursued in a Member State, account is to be taken, in the case of an employed activity, of working time and/or remuneration. The fact that less than 25% in respect of those criteria are met is to be an indicator that a substantial part of the activity is not being pursued in the relevant Member State (judgment of 19 May 2022, INAIL and INPS, C‑33/21, EU:C:2022:402, paragraph 63).

32The doubts raised by the referring court arise from the fact that the Dutch‑language version of Article 14(8) of Regulation No 987/2009 includes the term ‘mede’ (‘also’) in conjunction with the reference to the indicative criteria which must be taken into account in order to determine whether a substantial part of the employed activity of the person concerned is pursued in a Member State. The referring court infers from this that it would be permissible to accept criteria other than those of working time and/or remuneration listed in that provision.

33It should be noted that other language versions of Article 14(8) of Regulation No 987/2009, those of the German-, English-, French- and Latvian-language versions in particular, do not contain the word ‘also’.

34It is settled case-law that the wording used in one language version of a provision of EU law cannot serve as the sole basis for the interpretation of that provision, or be made to override the other language versions in that regard. Such an approach would be incompatible with the requirement for uniform application of EU law. Where there is divergence between the various language versions, the provision in question must be interpreted by reference to the purpose and general scheme of the rules of which it forms part (judgments of 25 March 2010, Helmut Müller, C‑451/08, EU:C:2010:168, paragraph 38 and the case-law cited, and of 21 March 2024, Cobult, C‑76/23, EU:C:2024:253, paragraph 25 and the case-law cited).

35As regards the context of the rules of which the provision in question forms part, it is clear from the very title of Regulation No 987/2009 that it is required to lay down the detailed rules for implementing Regulation No 883/2004. Article 14 of Regulation No 987/2009 is entitled ‘Details relating to Articles 12 and 13 of [Regulation No 883/2004]’ and paragraph 8 thereof was adopted ‘for the purposes of the application of Article 13(1) and (2) of [Regulation No 883/2004]’.

36It is therefore necessary, in interpreting Article 14 of Regulation No 987/2009, to take into account Articles 12 and 13 of Regulation No 883/2004.

37In that regard, it must be borne in mind that the provisions of Title II of Regulation No 883/2004, entitled ‘Determination of the legislation applicable’, of which Articles 12 and 13 of that regulation form part, constitute a complete and uniform system of conflict-of-law rules which are intended not only to prevent the simultaneous application of a number of national legislative systems and the complication which might ensue, but also to ensure that the persons covered by that regulation are not left without social security cover because there is no legislation which is applicable to them (see, to that effect, judgment of 16 November 2023, Zakład Ubezpieczeń Społecznych Oddział w Toruniu, C‑422/22, EU:C:2023:869, paragraph 50 and the case-law cited).

38As is apparent from recitals 1 and 45 of Regulation No 883/2004, the aim of that regulation is to coordinate the national social security systems of the Member States in order to guarantee that the right to the free movement of persons can be exercised effectively and, thereby, to contribute towards improving the standard of living and conditions of employment of persons who move within the European Union, while modernising and simplifying the rules contained in Regulation No 1408/71 (see, to that effect, judgment of 16 July 2020, AFMB and Others, C‑610/18, EU:C:2020:565, paragraph 63).

39That objective is implemented by Article 11(1) of Regulation No 883/2004, which provides that persons to whom that regulation applies are to be subject, in matters of social security, to the legislation of a single Member State only, which is to be determined in accordance with Title II of that regulation.

40To that end, Article 11(3)(a) of that regulation sets out the general rule that a person who pursues an activity as an employed person in the territory of a Member State is subject to the legislation of that Member State (see, to that effect, judgment of 16 July 2020, AFMB and Others, C‑610/18, EU:C:2020:565, paragraph 42).

41That general rule is, however, set out ‘subject to Articles 12 to 16’ of Regulation No 883/2004, since, in certain specific situations, the unrestricted application of that principle might in fact create, rather than prevent, administrative complications for workers as well as for employers and social security authorities, which could impede the freedom of movement of the persons covered by that regulation (see, to that effect, judgment of 16 July 2020, AFMB and Others, C‑610/18, EU:C:2020:565, paragraph 43).

42One of those specific situations is that covered by Article 13(1) of Regulation No 883/2004, namely the situation of a person who normally pursues an activity as an employed person in two or more Member States.

43Article 13(1) of Regulation No 883/2004 provides, in subparagraph (a), that a person who normally pursues an activity as an employed person in two or more Member States is to be subject to the legislation of the Member State of residence if he or she pursues a substantial part of his or her activity in that Member State, while subparagraph (b) of that provision states 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 that activity in the Member State where he or she resides is subject to the legislation of the Member State in which the undertaking or the employer has its registered office or place of business.

44The conflict-of-law rules laid down in Article 13(1)(a) and (b) of Regulation No 883/2004 guarantee that, where a person pursues an activity as an employed person in two or more Member States, the legislation of a single Member State is always applicable, that is to say, either the legislation of the Member State of residence of that person, if he or she pursues a substantial part of his or her activity there, or, failing that, the legislation of the Member State where his or her employer is established.

45In so doing, Article 13(1)(a) and (b) of Regulation No 883/2004 contributes to the objective set out in paragraphs 37 and 38 of the present judgment in that it lays down, while simplifying the rules introduced by the previous legislation, rules which derogate from the rule of the Member State of employment laid down in Article 11(3)(a) of that regulation precisely in order to avoid the complications which, otherwise, might arise if the latter rule were to be applied to situations involving the pursuit of activities in two or more Member States (see, to that effect, judgment of 16 July 2020, AFMB and Others, C‑610/18, EU:C:2020:565, paragraph 64).

46From that perspective, the aim of the derogating rules laid down in the provisions mentioned in paragraph 43 of the present judgment is to ensure that, in accordance with the rule of a single applicable legislation referred to in paragraph 39 of this judgment, employed persons working in two or more Member States are subject to the legislation of only one Member State, by establishing for that purpose connecting factors which take into account the objective situation of those workers in order to facilitate their freedom of movement (see, to that effect, judgment of 16 July 2020, AFMB and Others, C‑610/18, EU:C:2020:565, paragraph 65).

47It is in the light of those considerations that Article 14(8) of Regulation No 987/2009 must be interpreted when it refers to working time and/or remuneration in order to determine whether a quantitatively significant part of the worker’s overall activities is pursued in a Member State.

48In that context, it should be noted, first, that the last subparagraph of Article 14(8) of Regulation No 987/2009, according to which it is necessary to verify, in the context of an overall assessment of the situation of the worker concerned, whether the 25% threshold is reached, expressly refers to the criteria ‘mentioned above’, that is to say, in the case of activity as an employed person, those relating to working time and/or remuneration, to the exclusion of any other criterion.

49The fact that the criteria set out are verified in the context of an overall assessment of the situation of the worker concerned does not mean that other criteria may be added, but that all the employed activities of that worker must be taken into consideration.

50Second, the wording of that provision leaves little room for doubt that, if 25% of the criteria relating to working time and/or remuneration are not met, it cannot be found that a substantial part of the employed activity is pursued in the Member State concerned.

51To accept that a worker who has pursued less than 25% of all his or her employed activities in the territory of the Member State of residence may be subject to the legislation of that State pursuant to Article 13(1)(a) of Regulation No 883/2004 would not only be to disregard the derogating nature of the connecting factors laid down in Articles 12 to 14 of that regulation, including those relating to the Member State of residence, but also to create uncertainty in the application of the conflict-of-law rules laid down in Title II of that regulation, to the detriment of the simplicity which those rules are intended to establish as regards the application of connecting factors based on the objective situation in which the worker concerned finds himself or herself.

52The interpretation that a share of less than 25% of the criteria relating to working time and/or remuneration cannot be offset by taking into account other criteria is further confirmed by the explanatory notes provided by the Practical guide, a document which, by its very nature, has no binding legal force. That said, that guide is a useful instrument for the interpretation of Regulations No 883/2004 and No 987/2009. Thus, in the part of the document concerning the concept of ‘substantial part’ of the activity, it is stated that the criteria of working time and/or remuneration must be taken into account in order to ascertain whether the 25% threshold referred to in the last subparagraph of Article 14(8) of Regulation No 987/2009 is reached in the Member State of residence, which would then constitute an indication that a substantial part of all the activities of the worker concerned is carried out in that Member State. Although the Practical guide states that other criteria may also come into play, without, however, defining those criteria, it is clear from all the specific examples given that the pursuit of an activity as an employed person in the Member State of residence representing less than 25% in terms of working time and/or remuneration does not support a conclusion that the legislation of that State is applicable.

53Consequently, the Court finds that Article 14(8) of Regulation No 987/2009 must be interpreted as meaning that, in order for a person to be regarded as pursuing a substantial part of his or her activity as an employed person in the Member State of residence, the threshold of 25% of working time and/or remuneration in that Member State must be reached; the taking into account of other criteria is not liable to offset the failure to meet the criteria referred to above.

54It follows that, in a case such as that in the main proceedings, where it is common ground that the worker has pursued 22% of his activity as an employed person in the Member State of residence, which is below the 25% threshold referred to in the last subparagraph of Article 14(8) of Regulation No 987/2009, the conflict rule in Article 13(1)(a) of Regulation No 883/2004 cannot be applied to him, with the result that it is necessary to determine the applicable legislation in accordance with the conflict rule in Article 13(1)(b) of that regulation, which provides that a worker 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.

55It follows from the foregoing that there is no need to take into account other criteria in order to determine whether the worker concerned pursues a substantial part of his or her activity as an employed person in his or her State of residence.

56In the light of the foregoing, the answer to the first and second questions is that Article 14(8) of Regulation No 987/2009 must be interpreted as meaning that, in order to determine whether a person who normally pursues an activity as an employed person in two or more Member States carries out a substantial part of that activity in the Member State of residence, it is for the competent institution to ascertain, in the context of an overall assessment of that person’s situation, whether at least 25% of his or her working time and/or remuneration is completed and/or obtained respectively in that State. In that context, there is no need to take into account other circumstances or criteria.

The third question

57By its third question, the referring court asks, in essence, what period of time should be taken into consideration in order to assess, in the context of the overall assessment provided for in Article 14(8) of Regulation No 987/2009, whether the worker concerned pursues a substantial part of his or her activity as an employed person in the Member State of residence.

58In that regard, Article 14(10) of Regulation No 987/2009 provides that the institutions concerned must take account of the situation projected for the following 12 calendar months.

59Although that provision does not specify the starting point of the 12-month period to be taken into consideration, it is nevertheless clear from the wording of that provision that it concerns the following 12 months, since no provision of that regulation refers to the past situation of the worker concerned.

60Since the application of Article 14(10) of Regulation No 987/2009, taken together with Article 14(8) of that regulation, is reserved to cases where a worker pursues an activity in two or more Member States, it must be held that the starting point must be when the worker begins to pursue the activity in two or more Member States.

61Having regard to the foregoing considerations, the answer to the third question is that Article 14(8) and (10) of Regulation No 987/2009 must be interpreted as meaning that, in order to assess, in the context of the overall assessment of the situation of a person who normally pursues an activity as an employed person in two or more Member States, whether that person pursues a substantial part of his or her activity in the Member State of residence, account must be taken of his or her situation projected for the following 12 calendar months.

The fourth question

62By its fourth question, the referring court asks, in essence, what is the degree of discretion of the competent institution of a Member State in determining whether a worker has pursued a substantial part of his or her activity as an employed person, within the meaning of Article 13(1) of Regulation No 883/2004, in the Member State of residence.

63In the light of the answer to the first question, there is no need to answer the fourth question.

Costs

64Since 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.

Operative part

On those grounds, the Court (Sixth Chamber) hereby rules:

1.Article 14(8) 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, in order to determine whether a person who normally pursues an activity as an employed person in two or more Member States carries out a substantial part of that activity in the Member State of residence, it is for the competent institution to ascertain, in the context of an overall assessment of that person’s situation, whether at least 25% of his or her working time and/or remuneration is completed and/or obtained respectively in that State. In that context, there is no need to take into account other circumstances or criteria.

2.Article 14(8) and (10) of Regulation No 987/2009, as amended by Regulation No 465/2012,must be interpreted as meaning that, in order to assess, in the context of the overall assessment of the situation of a person who normally pursues an activity as an employed person in two or more Member States, whether that person pursues a substantial part of his or her activity in the Member State of residence, account must be taken of his or her situation projected for the following 12 calendar months.