Thanks to our friends at Brits is Spain
We have had a number of questions about postal votes for the upcoming General Election in the UK. Please note that it is now too late to apply for either a postal or proxy vote. If you’ve applied to vote by post, your postal vote must arrive at your Electoral Office in the UK by 10pm on 12 December. If you’re registered in Northern Ireland, you cannot vote by post from abroad. It is too late to apply to vote by proxy.
If you have still not sent your postal vote back here is information about the Spanish postal service international options: https://www.correos.es/…/pagina-internacional…/sidioma=en_GB. Other couriers services are also available.
For more information see https://www.gov.uk/voting-when-abroad