Since the creation of the single currency in the European Union on 1st January 2002, the Euro has become the local monetary unit. Its introduction was simultaneous in Spain, Germany, Austria, Belgium, Finland, France, Greece, the Netherlands, Ireland, Italy, Luxembourg and Portugal.
The banknotes, identical all over the European Union, have denominations of 500, 200, 100, 50, 20, 10 and 5 Euros. All coins have the same obverse face, but the reverse face is different in each country. Notwithstanding this fact, all coins are legal tender in all the member states that use the Euro.

Foreign currency can be exchanged in the bureau de change of El Corte Inglés Girocentre Shopping Centre (Carretera de Barcelona, 106). You can get until €300 per person and you need to show your passport.

http://www.xe.com/ucc/

When passing through Customs controls, citizens of countries that do not belong to the European Union must declare all articles constituting gifts or personal possessions the value of which is greater than 175 euros.

It is very normal to use a credit card to pay for purchases. The most common cards and those which are the best-known internationally are accepted in most shops, shopping centres and department stores, as well as in tourist establishments.
In case of loss of a credit-card issued by one of the following companies, the holders must report the loss as soon as possible by calling one of the telephone numbers listed below:
La Caixa: 900 300 081 - 952 200 202
6000 "la Caixa": 933 307 009
Visa: 900 991 124
Servired: 902 192 100
Xarxa 4B: 902 114 400
American Express: 902 375 637
Master Card: 900 971 231
Diners Club: 901 101 011