For a long time, there were no official steps to follow. There are now measures that can be followed so that British citizens living in Spain can apply for long-term residence after Brexit.
Transition period until December 31st, 2020
Following Brexit, there is a transition period ending on December 31st, 2020.
During this period, British citizens keep the same rights as other members of the European Union. Nevertheless, they need to follow a number of steps in order to normalise their situation and prove that they live in Spain.
It is recommended that you apply to normalise your situation during this transition period, since no steps have been established yet to do so after January 1st.
British citizens with a European Union Residence Certificate
Those citizens from the United Kingdom living in Spain with a European Union Residence Certificate (Green Card) will be able to apply for long-term residence quickly and easily.
The long-term Residency Certificate (TIE) must be obtained at the Police Headquarters showing your Green Card.
Those British citizens with a European Union Residence Certificate that has been valid for more than 5 years will be automatically granted residence for a period of 10 years. Those with a Green Card valid for less than 5 years will be granted a 5-year residence.
British citizens with NIE but without the European Union Residence Certificate
The steps to be followed by British citizens with a Foreign Id (NIE) but without a Green Card are not as straight forward.
Having a NIE does not mean having residence. Therefore, in order to obtain a long-term Residence Certificate (TIE) they need to formally request their residence in Spain at the Immigration office.
Please bear in mind that it doesn’t matter if you usually live in Spain, from July 1st, 2020 British citizens can no longer request the European Union Residence Certificate (Green Card). They must obtain their residence through the Immigration Office.