The rules of origin can be challenging. The UK Trade Cooperation Agreement (TCA) enables duty-free movement of goods between Great Britain and the EU in most cases, but the origin of the goods is crucial. To qualify for duty-free status, the goods must have preferential origin, meaning they are wholly obtained in the qualifying territory or undergo sufficient processing there. The TCA does not cover goods that are merely in "free circulation," meaning goods that have already paid duties in one territory may not automatically qualify for duty-free status in the other unless they undergo significant processing to change their origin status.
When claiming a reduced rate of duty proof of Origin is the most vital part.