BECOME RESIDENT IN SPAIN
1st time application: Any EU citizen intending to stay in Spain for more than three months is obliged to register to be added to the Central Register of Foreign Nationals (Registro Central de Extranjeros) at a Foreigners' Office (OficinaExtranjero) in the area in which they intend to reside.
Following new legislation introduced by the Spanish government in July 2012, all EU citizens who wish to stay in Spain for longer than three months are asked to prove that they have the sufficient financial means to support themselves and any dependents. They are also required to provide proof of private or public healthcare insurance.
You should be aware that the registration certificate is literally a piece of paper. While it does officially prove your Spanish residency, it is not a valid form of identification in Spain – only your own national passport is acceptable as ID.
UK PENSIONERS: Healthcare is provided to UK state pensioners resident in Spain on the same basis as healthcare given to Spanish pensioners. Therefore, healthcare changes that are applicable to Spanish state pensioners are equally applied to all UK state pensioners.
PROOF OF HEALTHCARE: If you are applying for your residence certificate, you are asked to show proof that you are covered for healthcare in Spain when making your application.
RENEWAL: EU citizens who already hold an EU Residence Card do not need to re-register until the card expires, at which point they should proof financial means and private or public healthcare insurance.
TAX PURPOSES: When you live in Spain for more than 183 days in one calendar year you become legally liable to be charged Spanish Income Tax as a Resident. The 183 days do not have to be consecutive.