But it's the U.K. regional passport authority, not Spain. I've already been mugged by the Spainsih this month, with my quarterly taxes, autonimo, and gestor fees.
You need a decent break in your earnings when you are Autonimo, quarterly Taxes & Gestors Fees, been there and done that and wouldn't wish to go back there, and I managed to be Autonimo trading as a Bisuteria/market trader instead of a Constructor which saved a few bob.