There is a new tax treaty between the UK and Spain to avoid double taxation. Details are on this link. http://www.lamoncloa.gob.es/IDIOMAS/9/Gobierno/News/2013/20130325_SpainUKTax.htm?gfe=1 (http://www.lamoncloa.gob.es/IDIOMAS/9/Gobierno/News/2013/20130325_SpainUKTax.htm?gfe=1)