Did you know that "roaming without surcharges" exists within the European Union? Calls (to mobiles and landlines), text messages (SMS) and data services are charged at the same rates as in your home country.
If you receive a call or text message during your stay abroad, you will not have to pay any additional costs either.
To call Spain or a Spanish number from abroad, you must first dial +34 and then the telephone number. The + symbol appears on your mobile phone when you press and hold the 0 key.
Find out all the information about roaming here and international calls here.
Remember that to have internet abroad you must have your APN configured.
For international calls outside of roaming and calls to premium rate numbers you can consult this document.