The following licence requirements have been cut & pasted from a well known car hire consolidator (using a variety of well known car hire companies) for Spain:-
�Licence requirements: Full UK licence that has been held for at least two years
If you have a new style Photo Driving licence which commenced in July, 1998 then you must bring both parts of the licence with you
Old style paper licences (which do show endorsements) will be valid until their expiry date however you must also produce a valid passport or another form of ID
If you do not have an EU driving licence, an International Driving Licence will be required in addition to your full licence from your country of residence.�