From the gov.uk website
Driving in Spain
If you are resident in Spain and have not exchanged your UK licence for a Spanish one, your UK licence will continue to be recognised until 30 June 2021.
If you were resident in Spain before 1 January 2021 and registered your details with the DGT (Spanish Traffic Authority) before 30 December 2020, you must make an appointment with the DGT to complete the exchange of your UK licence by 30 June 2021. You will have to show proof you are registered as a resident at the appointment.
You will have to give your UK licence to the Spanish Traffic Authority at your appointment. They will provide you with a temporary driving permit (‘autorización temporal para conducir’) to use until your Spanish licence is processed. This document is only valid in Spain and not in any other country
Read the Spanish Traffic Authority’s guidance on how to get an appointment and the documentation you must provide (use the option in the top-right hand corner to translate page to English).
The rules for exchanging a licence have not been confirmed for those that did not register their details with the DGT or moved to Spain after 1 January 2021. We will update this page when more information is available.
Driving in the UK with a Spanish licence
You can use your Spanish licence in the UK for short visits, or exchange it for a UK licence without taking a test. We will update these pages if there are any changes to the rules, as soon as information is available.
Lost, stolen or expired UK licences
If you live in Spain, you will not be able to renew your driving licence in the UK. If your UK licence is lost, stolen or expired, you will need to apply to the Driver and Vehicle Licensing Agency (DVLA) for a ‘certificate of entitlement’ to be able to apply for a Spanish driving licence.
For information on driving in Spain, read our guidance on:
what you need to drive abroad
driving rules in Spain
Bringing a UK-registered vehicle to Spain
Read our guidance on taking a vehicle out of the UK.
If you register as a resident or spend longer than 6 months of the year in Spain, you must register your vehicle with the Spanish authorities and you may need to pay some taxes.
You may be exempt from some of these taxes. If so you will need certificates of exemption.