SolvedNIM33035 | Special Cases: International going to or coming from abroad EEA Regulations 883/04 (After 1 May 2010): Employed or self-employed workers
From HM Revenue & Customs · National Insurance Manual
Note: This page is under review and the content may only be appropriate to periods beginning before 1 January 2021 and for those covered by a Withdrawal Agreement. A new International manual is under development and will be published in due course.
Article 11(3)(a) of Regulation 883/2004 of the European Parliament and of the Council of 29 April 2004 on the coordination of social security systems
A person going abroad to work in an EC Member State will, unless subject to one of the exceptions in Article 12-16 be subject only to the legislation of that Member State and no longer insured in the United Kingdom.
Article 11(3)(a) states:
“A person pursuing an activity as an employed or self-employed person in a Member State shall be subject to the legislation of that Member State.
As a general rule this means that a person who is within the personal scope of Regulation 883/2004, and working as an employed earner, or a self-employed earner, in the United Kingdom, will be subject to the legislation of the United Kingdom unless they come within one of the exceptions in Article 12-16 of Regulation 883/2004.
Generally you pay social security contributions in the country where you work even though you reside in another Member State.
National insurance liability starts as soon as the person starts working in the United Kingdom.