Back arrowButton/calendaricon/lockicon/sponsor
Open search
Close search
Call us on0808 168 5874

What is an A1 form and how to apply?


UK employees have been able to travel to the EU on business with ease for the last 25 years. However, few have been aware of certain rules associated with business travel between EU member states.
A certain requirement that may have passed UK employers by, is the need to have an A1 form when conducting business in the EU. 
An A1 form is simply a certificate issued by HMRC that proves an individual pays UK NICs. Why then would a UK worker or employer need to prove they pay UK NICs and why does it matter in the context of travelling to the EU on business?
This requirement has long been in place and in July 2020, the EU increased its enforcement of the rules for business travel, including the requirement to have an A1 form, before you travel.
As such, we have seen members being turned away from countries such as France and Spain as their workers have arrived without their A1 forms. 

But why does it matter? 

There is an EU rulebook for the temporary movement of workers between EU Member States, known as the Posted Workers Directive. Within this, a worker temporary working or visiting another Member State would be required to pay local NICs of that Member State on Day 1 of arrival, something UK employers would want to avoid.
But the rule only applies if the worker can prove they already pay social security in their host state – in our case this means the UK. Therefore, in advance of travel, UK employers and workers need to obtain an A1 form to avoid paying local social security in the Member State they will be travelling to.
There are two types of A1 form that UK employers should be aware of; a single-trip A1 form (you’ll need to fill out a form CA3822 in all cases) and a multi-state A1 form (CA8421).
The former is suitable for workers visiting or working in just one Member State within a single trip. The latter, is suitable for workers visiting or working in multiple Member States within one trip before returning to the UK.
Each individual who travels to the EU will require their own A1 form and will need to state the length of time they intend to visit that Member State. 
However, A1 forms are valid for 24 months and if UK employers travel frequently, it would be sage to include on the form that workers could be visiting any Member State at any time for a 24 month period. This would save the UK employer and workers from updating their A1 form each time they made a trip and cuts down on the red tape.
So remember, before you travel, apply for an A1 form and send a copy in advance to the local labour authority in the State you are visiting; PS. it helps to travel with a copy as well!

Who needs an A1 form?

  • If an employee travels to the EU for work, either on a business trip as a business visitor, or as a posted worker to provide a service, they will need an A1 form.
  • Both business visitors and posted workers are covered by the UK social security system, and will need an A1 form.
  • The business visitor or posted worker can continue to pay UK NICs whilst they are in the EU Member State.
  • In order to prove that UK NIC is paid, the business visitor or posted worker must carry their A1 form, obtained from HMRC.
  • A1 forms are generally valid for up to 24 months however, one can choose a shorter validation length for the time they are abroad.
  • A1 forms prove to the EU Member State that the employee travelling pays social security in the UK and doesn’t need to pay in the EU country where they are travelling. A1 forms are not available for chain posting.


Do I need an A1 form per trip?

No. An A1 form is valid for as long as it is needed up to 24 months. Many manufacturers are frequent business travellers, and would have an A1 form valid for as long as is needed -- up to 24 months. The A1 application process is needs based, so if a worker is travelling for a shorter period, e.g. 3 months, then they would apply for an A1 form valid for this period.

Why is it only now do I need one? 

In 2018, the EU Commission amended the posted workers directive. The changes were implemented 31 July 2020 for all EU Member States, though most countries have already incorporated these into law. Existing rules ask that those who travel to the EU for business or work provide their A1 forms. Since July 2020, there is increased enforcement to ensure travellers comply and fines are being issued for non-compliance.

Where can I get an A1 form? 

The national insurance page on the site provides A1 application forms. HMRC will issue the approved A1 form. If you are a director of your own limited company, then your company needs Form CA3821 and Form CA3822 (this form is for each individual employee for issue of Form A1).

Does everyone need an A1 form?

If you are travelling to the EU for business or work, including whether you’re a business visitor or posted worker you will need an A1 form.

How do I use my A1 form?

You will need to bring, show and send in advance your A1 form before you travel. This means providing a copy of an A1 form to the host state and carrying it with you when you cross borders.

Available resources

Blog / Ceridian / Leaving the EU