Social Security for Posted Workers: Which Country's Law Applies under Regulation 883/2004

An employee posted from one State to another therefore stays insured at home for an anticipated duration of up to 24 months under Article 12(1), and pays contributions in one State only.

These rules have applied since 1 May 2010, together with the implementing Regulation (EC) No 987/2009, in the 27 EU Member States, in Iceland, Liechtenstein and Norway through the EEA Agreement, and in Switzerland: 31 States in total. Regulation (EU) 2026/2359 has amended both Regulations since 1 November 2026, and most of its Title II changes apply from 2 November 2028. These Regulations decide social security only, one part of the EU rules for posted workers.

This guide sets out the two Regulations and the States they cover, the Title II principles and special groups, a decision table, and what applies today and from 2 November 2028, with five detailed guides for the individual rules.

What Is Regulation 883/2004?

Regulation (EC) No 883/2004 of 29 April 2004 is the EU regulation on the coordination of social security systems; it applies directly in every Member State and has applied since 1 May 2010 (Article 91 of Regulation (EC) No 883/2004). The Regulation was published in OJ L 166, 30.4.2004, p. 1, under CELEX number 32004R0883, and EUR-Lex holds the consolidated text of Regulation (EC) No 883/2004. As a regulation, it needs no national transposition act (Article 288 TFEU), unlike Directive 96/71/EC and Directive 2014/67/EU.

Title II, "Determination of the legislation applicable", decides which single national legislation covers a person, in six articles listed below with their official headings.

1. Article 11: General rules
2. Article 12: Special rules
3. Article 13: Pursuit of activities in two or more Member States
4. Article 14: Voluntary insurance or optional continued insurance
5. Article 15: Auxiliary staff of the European Communities (the 2004 heading)
6. Article 16: Exceptions to Articles 11 to 15

Regulation (EU) No 465/2012 of 22 May 2012 amended Regulation (EC) No 883/2004 and gave Articles 11(5), 12(1) and 13(1) their current wording. Regulation (EU) 2026/2359 of 7 October 2026 amends Title II again, with provisions applying from 1 November 2026 and from 2 November 2028.

Regulation 987/2009: How the Rules Are Applied

Regulation (EC) No 987/2009 of 16 September 2009 lays down the procedure for implementing Regulation (EC) No 883/2004 and has applied since 1 May 2010 (Article 97 of Regulation (EC) No 987/2009). It was published in OJ L 284, 30.10.2009, p. 1 (CELEX 32009R0987), and it repealed Regulation (EEC) No 574/72 with effect from 1 May 2010 (Article 96). EUR-Lex publishes the consolidated text of Regulation (EC) No 987/2009.

Articles 14 to 21 of Regulation (EC) No 987/2009 carry the Title II procedure. The five that matter most for posting are listed below.

• Article 14: details relating to Articles 12 and 13 of Regulation (EC) No 883/2004
• Article 15: the information the employer or person gives to the institutions concerned
• Article 16: the procedure for Article 13 (work in two or more Member States)
• Article 18: the procedure for Article 16 (exception agreements)
• Article 19: the attestation of the applicable legislation, issued as the portable document A1

Where the Coordination Rules Apply: EU, EEA and Switzerland

The Regulation applies in the 27 Member States and, through two agreements, in Iceland, Liechtenstein, Norway and Switzerland: 31 States in total. For the EEA, Annex VI of the EEA Agreement carries the coordination rules: Joint Committee Decision 076/2011 of 1 July 2011 incorporated Regulation (EC) No 883/2004, and the incorporation has been in force in the EEA since 1 June 2012, as EEA-Lex records. Switzerland applies the Regulation in its relations with the EU through Annex II of the Agreement on the Free Movement of Persons, since 1 April 2012. Between Switzerland, Iceland, Liechtenstein and Norway, the revised EFTA Convention (in force since 1 June 2002) has applied Regulation (EC) No 883/2004 since 1 January 2016, according to the Swiss Federal Social Insurance Office.

Article 8 of Regulation (EC) No 883/2004 governs the Regulation's relations with other coordination instruments. Within its scope, the Regulation replaces the social security conventions concluded between Member States, while agreements with third countries are not replaced. The United Kingdom is not one of the 31 States.

From Regulation 1408/71 to Regulation 883/2004

Regulation 883/2004 replaced Regulation (EEC) No 1408/71 and its implementing Regulation (EEC) No 574/72 on 1 May 2010, and the portable document A1 replaced the E 101 certificate on the same date. The E 101 attested the applicable legislation under the old Regulations; the current document is the A1, never an E 101.

The old rules did not end everywhere on 1 May 2010. Regulation (EEC) No 1408/71 (CELEX 31971R1408) continued to apply with Switzerland until 31 March 2012, and between Switzerland and the other EFTA States until 31 December 2015. Each end date is the day before Regulation (EC) No 883/2004 took over in that relationship. Regulation (EEC) No 574/72 keeps a limited effect under Article 96 of Regulation (EC) No 987/2009.

The Title II Principles: One Legislation at a Time, the Place of Work First

Title II rests on two principles: a person is subject to the legislation of one Member State only (Article 11(1) of Regulation (EC) No 883/2004), and that is in principle the legislation of the State where the work is done (Article 11(3)(a)). Lawyers call the place-of-work rule lex loci laboris; the Latin label is doctrinal and does not appear in the Regulation. It applies to employed and self-employed persons alike. Article 11(3) of Regulation (EC) No 883/2004 also covers persons who do not work in a State: a person receiving unemployment benefits under Article 65 from the State of residence is subject to that State's legislation (point (c)), a person called up or recalled for military or civilian service to the legislation of that State (point (d)), and anyone else to the legislation of the State of residence (point (e)).

The special rules of Articles 12 to 16 of Regulation (EC) No 883/2004 depart from the place-of-work rule. Posting keeps the sending State's legislation for an employee whose work has an anticipated duration of up to 24 months (Article 12(1)), and for a self-employed person pursuing a similar activity in another State (Article 12(2)). A person who normally works in two or more Member States comes under one legislation fixed by Article 13. Article 16(1) lets the States agree exceptions to Articles 11 to 15 in the interest of persons or categories of persons. The Administrative Commission for the Coordination of Social Security Systems explains these rules in its Practical Guide on the applicable legislation (December 2013), which is not legally binding.

Each Title II rule ends in one competent legislation, and the institution of that State attests it. Under Article 19(2) of Regulation (EC) No 987/2009, the institution of the State whose legislation applies certifies it at the request of the person or the employer. The attestation shows which legislation applies; it is the portable document explained under A1 certificate.

Civil Servants, Seafarers and Air Crew

Three groups follow their own Article 11 rule rather than the place of work: civil servants remain subject to the legislation of the Member State to which their employing administration belongs (Article 11(3)(b)), seafarers to the flag State (Article 11(4)) and flight and cabin crew to the State of their home base (Article 11(5) of Regulation (EC) No 883/2004).

For civil servants, the German liaison body DVKA states that German law applies to German civil servants working temporarily or habitually in other Member States, regardless of the duration or the share of that work, telework included. A German civil servant seconded to another Member State for three years therefore stays under German law, although the 24-month posting limit has passed.

Seafarers are subject to the legislation of the flag State of their vessel (Article 11(4) of Regulation (EC) No 883/2004). The flag rule has a limit: in C-631/17 SF (Third Chamber, 8 May 2019), the Court of Justice applied Article 11(3)(e) to a seaman working for an employer established in a Member State on a vessel flying the flag of a third country outside EU territory, who kept his residence in his Member State of origin, so the legislation of his Member State of residence applied. For flight and cabin crew, Article 11(5) has applied since 1 November 2026 in its amended wording, which refers to Regulation (EU) No 965/2012 for the home base. These three rules are Article 11 rules, not postings, so the 24-month limit of Article 12 does not apply to them.

Five Title II Topics in Detail: Posting, Two or More States, Exceptions, Telework and the Revision

Five guides take the Title II rules further: the Article 12 posting rule, work in two or more Member States, Article 16 exception agreements, cross-border telework and what Regulation (EU) 2026/2359 changes. Each guide answers one question with its legal basis in Regulation (EC) No 883/2004 or Regulation (EC) No 987/2009, and marks the rules that change on 2 November 2028. These rules decide the applicable legislation only; the A1 request, the host State's posting declaration and the documents kept at the workplace are separate steps.

Every obligation before, during and after a posting is listed in the posting compliance checklist.

Which Country's Social Security Law Applies in Each Situation

The applicable legislation follows from the first Title II rule that fits the situation: the place of work under Article 11(3)(a) of Regulation (EC) No 883/2004, unless a special group rule, the posting rule of Article 12, the multi-state rule of Article 13 or an Article 16 agreement applies. The table reads from top to bottom, and the first matching row gives the State whose legislation applies today. A posting under Article 12(1) of Regulation (EC) No 883/2004 needs an anticipated duration of not more than 24 months, and the employee must not be sent to replace another person. For multi-state work, a share of less than 25 % of working time and/or remuneration in the State of residence is an indicator that a substantial part of the activity is not pursued there (Article 14(8) of Regulation (EC) No 987/2009). Beyond 24 months, only an agreement under Article 16(1) of Regulation (EC) No 883/2004 keeps the home legislation, and EU law sets no maximum period for such an agreement.

Habitual cross-border telework follows a collective agreement concluded under Article 16(1) of Regulation (EC) No 883/2004. Under the Framework Agreement, telework of at least 25 % and less than 50 % of working time in the State of residence can stay under the legislation of the employer's State, and 23 States had signed it as of 5 November 2026, according to the Belgian depositary. The table sets out the rules and their legal basis; it does not decide which legislation applies to a named employer or worker, which is the competent institution's decision.

What Applies Today and What Applies from 2 November 2028

Regulation (EU) 2026/2359 of 7 October 2026 has amended Regulations 883/2004 and 987/2009 and has been in force since 1 November 2026, but most of its Title II changes, including the new posting rules, apply only from 2 November 2028. The Commission proposed the amendment on 13 December 2016 (COM(2016) 815, procedure 2016/0397(COD)). After the Coreper letter confirming the agreement on 29 April 2026, the European Parliament's position of 7 July 2026 and the Council's adoption on 28 September 2026, Regulation (EU) 2026/2359 was published in OJ L, 2026/2359, 27.10.2026. It entered into force on the first day of the month after publication (Article 3 of Regulation (EU) 2026/2359).

Since 1 November 2026, the first set of amended provisions applies: Articles 11(5), 75a, 87b and 88 to 88c of Regulation (EC) No 883/2004, and Article 1(2) and Article 19(2) and (3) of Regulation (EC) No 987/2009. Under Article 19(2) and (3) of Regulation (EC) No 987/2009 as amended, the A1 is issued in a standardised format and only after a proper assessment of the facts.

From 2 November 2028, the second set applies: Articles 11(2), 12 and 13(4a) and (5) of Regulation (EC) No 883/2004, and Articles 5(2) to (5), 14, 15, 16, 19a, 20(3) and (4) and Annexes 5 and 6 of Regulation (EC) No 987/2009. Until that date, Article 12 of Regulation (EC) No 883/2004 applies in its current wording, read with the indications of Administrative Commission Decision No A2 of 12 June 2009.

Persons sent before 2 November 2028 keep the old Article 12 for that posting (Article 87b(4) of Regulation (EC) No 883/2004). Article 87b(4) also sets a Title II transitional period ending on 2 November 2036; requests to leave it made on or before 2 January 2029 are deemed submitted on 2 November 2028, and the period does not cover Article 12. The table below applies in the EU as of 5 November 2026; the take-over of Regulation (EU) 2026/2359 by Iceland, Liechtenstein, Norway and Switzerland is pending as of 5 November 2026.

What Regulation 883/2004 Does Not Decide

Regulation 883/2004 decides social security only: host-State pay and labour law, the UK relationship and cover outside the 31 States follow other instruments. Each of the three follows its own act, periods and documents.

Host-State Pay and Labour Law: The Other Clock

Pay and working conditions in the host State follow Directive 96/71/EC, not the Regulation, and its durations run on a separate labour-law clock. A posted worker is entitled to the host State's terms on the matters listed in Article 3(1) of the Directive, as transposed into national law, so host pay and conditions are set by the Posting of Workers Directive.

Under Article 3(1a) of Directive 96/71/EC, long-term posting starts after 12 months, or 18 months on a motivated notification. The social security clock of Article 12 of Regulation (EC) No 883/2004 counts an anticipated duration of up to 24 months, and the two periods never replace each other.

The UK-EU Protocol on Social Security Coordination

Since 1 January 2021 postings between the UK and the EU follow the Protocol on Social Security Coordination of the EU-UK Trade and Cooperation Agreement, not Regulation 883/2004. Under Article SSC.11(1)(a)(i) and (1)(b) of the Protocol on Social Security Coordination, a detached worker, employed or self-employed, stays under the sending State's legislation for up to 24 months, and all Member States have opted in to the detached-worker provision.

The Protocol has no equivalent of Article 16 of Regulation (EC) No 883/2004, the article on exception agreements. The documents UK employers use and the HMRC route are covered under posting to and from the United Kingdom.

Cover Outside the EU, EEA, Switzerland and the UK

Outside these 32 States Regulation 883/2004 does not apply: a bilateral social security agreement decides cover where one applies, and the sending institution issues a certificate of coverage, not an A1. Article 8 of Regulation (EC) No 883/2004 leaves agreements with third countries in place. No A1 exists for postings to the USA, India, Canada, Turkey, China, Japan, Australia, Korea, Brazil or Serbia; each agreement sets its own maximum period and its own certificate.