Are you British and a legal resident in Spain? Or are you planning to live in Spain?
If you are a British citizen and a resident of Spain:
In this case you should be in possession of an EU residency card (such as a Spanish NIE). If so, you will have to switch it for a foreign residency card before December 31st, 2020. If you need our assistance to do this, please fill out the contact form and we will get in touch with you.
If you are a British citizen and planning to live in Spain...
In conclusion, if you are living in Spain or planning to move, we strongly recommend that you start the application for your foreign ID card. This will save you time and you avoid the risk of losing the benefits you had as an EU citizen while you apply for your residency.
The British government released a comprehensive guide about residing in Spain.
Brexit preparedness checklist for UK companies doing business in the EU (Sept 2019)
Brexit and the EU rules on direct taxation
Tax office: VAT consequences of Brexit (in Spanish)
FAQs from the Spanish government for UK citizens residing in Spain (updated July, 2020)
If I become a citizen of Spain, will I need to renounce my British citizenship? This is up to the British authorities if they discover that you have Spanish citizenship.