Spain is a popular vacation destination with a lot of prepaid data SIM card offers available. Attention: Prices on the Spanish islands may vary!
In Spain there are 4 network operators (Movistar, Vodafone, Orange and Yoigo) and a lot more providers. There is a lot of competition with small resellers. In general prepaid SIM cards of the bigger providers are more easy to purchase, but a bit more expensive.
All SIM cards have to be registered via passport.
Network frequency bands are European standard.