You can apply to HMRC to be added to the REX system if you’re a:
UK company that exports materials to Generalised System of Preference (GSP) beneficiary countries, and they are then used to manufacture products to be imported back into the EU (known as ‘bilateral cumulation of origin’)
UK established re-consignor of GSP goods to other EU member states
UK company that exports to another third country that has a trade agreement with the EU, and where the REX system applies (Canada, for example)
To apply online, you need a Government Gateway user ID and password. If you do not have a user ID you can create one when you apply online.
REX system registration will allow you to issue statements of origin when the value of the consignment is over 6,000 euros.
You can only apply for REX system registration if you’re one of these specific types of traders.