From the 6th July 2020, UK citizens already resident in Spain can apply  for the TIE Foreigners Identity Card.

The new process was brought in to comply with Article 18.4 of the Withdrawal Agreement (WA) with the UK leaving the European Union. It is designed to provide physical certification of all the rights and protections British citizens are entitled to under that Agreement. While both the Spanish Government have stated that it’s not yet obligatory for existing legal residents to exchange to this new card, they recommend it.

Here are some reasons why  it is a good idea:

• The TIE card is a biometric photocard, secure and recognised as a proper ID. You won’t need to carry your passport around in Spain. The card is proof that your rights under the Withdrawal Agreement are enshrined by and explicitly mentioned on the new TIE card.
  
• A TIE will reduce wait times at Schengen borders and recommend that UK citizens secure a TIE to help with smooth travel. The EU has made it clear that the TIE will «facilitate administration processes and border crossings» which has got to be a good thing. Your TIE is your right to enter your country of residence, Spain. The TIE will exempt the holder from the  ETIAS visa scheme when this starts to be necessary..
  

Depending in which province you live and date of the year you try to get an appointment at National Police Extranjeria’s it can be easier or harder to get, At the moment we write this post we are getting appointments easily in most of the provinces of our clients.

So it’s worth not putting off until tomorrow, as eventually, it will become compulsory and the National Police may be collapsed again if soon an ending note, the opening bars to «Ode to Joy», the EU anthem, are on the new TIE card’s back.