On 24 December 2020, the European Union (EU) and the United Kingdom (UK) agreed the EU-UK trade and Cooperation Agreement including a Protocol on Social Security Coordination, governing the social security position of individuals who move between the UK and the EU from that date.
We refer to the GMS Flash Alert 2021-005 (5 January 2021) and GMS Flash Alert 2021-010 (8 January 2021) for a detailed overview and the explanatory commentary of the rules included in the Protocol on Social Security taking effect from 1 January 2021 (after implementation procedure is completed) and their consequences.
As with respect to contributions, the Protocol on Social Security refers to the work state principle (you pay where you work), however certain exemptions apply.
Please find below an overview of the most frequent cross-border situations (UK – EU Member States) and the applicable social security principles in a nutshell:
This category of individuals can benefit from the ongoing social security coverage in their home country in line with the EU Regulations. An A1/E101 declaration confirming the applicable social security legislation prior to 1 January 2021 should in principle have been obtained. In cases where the A1/E101 was not (timely) obtained, the factual situation will in principle prevail.
An individual who works substantially (i.e. 25% or more of his/her working time or remuneration) in his/her country of residence will be subject to the social security in that country. And individual who does not meet the 25%-test, should be subject to the social security in the country where his/her employer is established. Please note that for more complex cases (multiple employers) different rules apply.
Posted employees can remain subject to the social security legislation of their home country, given certain conditions are met and this for a limited time of 24 months.
However, in order to benefit from this provision, the EU Member States have to opt-in for this provision by the end of January 2021.
We can inform you that the Belgian social security authorities have already confirmed that they will opt-in. An official statement is yet to follow.
As with respect to social benefits, please note that the Protocol covers limited matters (e.g. sickness benefits, maternity/paternity benefits, etc.). The Protocol does refer to principles known from the EU Regulations on the coordination of Social Security Legislation such as the aggregation of insured periods and the exportability of certain benefits. For a full overview, we refer to the aforementioned Flash Alerts.
 Please see EUR-Lex - 22020A1231(01) - EN - EUR-Lex (europa.eu)