U.K. passports?
If yes, no need to worry. For travel within the European Union passports of union members just need to be valid on arrival at the country.
The right to move freely is granted to you on grounds of your Union citizenship and these documents confirm that you are indeed a Union citizen.
It is irrelevant whether you are travelling for professional or private reasons, whether you are going to work in an employed or self-employed capacity or whether you are simply a tourist.
Beside the requirement to hold a valid identity card or passport, there are no other conditions or formalities for the purpose of entry to the host Member State. However, the immigration officers are entitled to check the validity of your identity card or passport.
Immigration officers may not:
• require you to present an identity card with machine readable zone, a recent model of identity card or a passport with validity at least another 3 months … if the identity card or passport is valid, that is all you need;
• ask you to produce any documents other than a valid identity card or passport, such as to furnish proof of means to support yourself, travel tickets, employment certificate, pay slips, bank statements, proof of accommodation, means of subsistence, medical certificate …
• ask you how much money you have to spend;
• ask you questions regarding the purpose and duration of your trip;
• affix an entry stamp on your identity document or passport on arrival authorising you to enter the national territory.
http://ec.europa.eu/youreurope/nav/en/ci… ..
http://www.fco.gov.uk/en/travel-and-livi… ..
http://www.maec.es/subwebs/Consulados/Lo… ..