Guide to posting workers to the United Kingdom

Since Brexit, the rules applicable to posting workers to the United Kingdom have changed, as the country is no longer a member of the European Union.

It is therefore essential to include an immigration perspective to ensure full compliance.

1) Immigration requirements for posting workers to the United Kingdom

In principle, a work permit is required to work in the United Kingdom.

However, for assignments of less than 6 months, the Home Office allows certain activities to be carried out under a business visitor exemption (i.e. without a work visa):

• Attending interviews, meetings, conferences, and seminars
• Negotiating and signing agreements and contracts
• Participating in trade fairs to promote the company
• Undertaking professional training, provided the employee works overseas and the training is not available in their home country
• Delivering one-off lectures, provided they are not for profit
• Conducting site visits or inspections
• Supervising the delivery of goods and services provided by a UK company to a foreign entity
• Providing training or sharing knowledge on internal projects with UK employees (intra-group mobility only)
• Installing, dismantling, repairing, maintaining, or advising on equipment, software, or IT systems, where a contract exists between the foreign company and a UK entity

2) Insurance and Social Protection obligations

Following Brexit, the EU–UK Trade and Cooperation Agreement provides for the continuation of a posting framework, with specific rules governing the coordination of Social Protection between the United Kingdom and EU Member States.

• The A1 certificate (issued in the country of origin) remains mandatory. It is a key document in the context of posting workers between the EU and the UK, as it confirms that the employee remains affiliated to their home Social Protection system during the assignment, thereby avoiding double contributions.
• The general principle remains: the host company (your client) is responsible for operational safety, while the sending employer (you) remains responsible for informing, training, and providing equipment to employees.

The United Kingdom has also entered into several bilateral Social Protection agreements with non-EU countries. This includes countries from the former Yugoslavia, such as Serbia.

• In such cases, a Certificate of Coverage (CoC) must be obtained instead of an A1 certificate.

3) Summary of requirements for posting workers to the United Kingdom

French & UK nationals	Less than 6 months	More than 6 months	Comments
ETA (Electronic Travel Authorisation)	✅	❌	Requirements vary for other nationalities
Work visa	❌	✅	Verify whether the assignment falls under an exemption; otherwise required even for short assignments
Posting declaration	❌	❌
A1 certificate or CoC	✅	✅	Depending on the country of origin and applicable agreements with the UK
Compliance with employment law	✅	✅	Working conditions, safety, rest periods
Document retention	❌	❌
Local registration	❌	❌