The Northern Ireland Protocol governing trade between Great Britain and the region comes into effect when the Brexit transition period ends at 11pm on New Year’s Eve. Here are answers to some of the main questions about the protocol, its origins and how it will work. – Why was the protocol needed? It was the resolution to the main sticking point in the Brexit divorce talks – the Irish border. In order to avoid disrupting cross-border trade and a return of checkpoints along the politically sensitive frontier, the EU and UK essentially agreed to move new regulatory and customs processes to the Irish Sea. That means the checks are now focused on trade between Great Britain and Northern Ireland.