Economy A simple guide: 10 things to know about the Brexit deal From fishing quotas and free movement to mobile roaming charges and pet passports – much will change on January 1. An electronic billboard shows a British government information message advising business to prepare for Brexit, in London, December 4, 2020 [File: Toby Melville/Reuters] An electronic billboard shows a British government information message advising business to prepare for Brexit, in London, December 4, 2020 [File: Toby Melville/Reuters] 28 Dec 2020 -- tape requirements. Ireland, the EU country most affected by Brexit, estimated in September that import and export declarations could increase 12-fold to as many as 20 million per year.