Currencies, cards and money in Zaragoza
Only Euro. It is the official currency... but let's talk about money in Zaragoza
Currencies accepted
Only Euro coins/banknotes will be accepted anywhere. I haven't seen any place accepting other currencies incluiding US dollars, Swiss Francs or British Pound.
Until 2001 the official currency was Spanish Peseta. Even though a lot of years are run since then, it would be possible to find something (specially those things with a higher price) written with the two currencies, although peseta is not used anymore.
Where can I exchange money?
As far as there are less people with foreing currencies who ask for exchange, it is not usual to see exchange business.
But in almost all banks (never mind which one), all most common currencies will be changed with the official rate and usually a fee (not high. When there were a lot of exchange agencies, banks had the lowest fees).
Banks usually open 8:00 to 8:30 and close 14:00 to 14:30. Depending of the bank, they can open on Thursday evening.
Some specific bank agencies have a different timetable (for instance one of CAI in P.Independencia and two of CAI and ibercaja in the station, as well as several in shopping centres but also several banks for all their agencies can open several hours in the evening), incluiding sometime saturdays.
It is enough to arrive to the desk with the foreing banknote (they will not accept coins) and they will give you the equivalent into euro currency.
Main hotels can exchange money too (and obviously their schedule is longer than banks) but they can have worst rates or fees.
Can I use my credit card?
VISA and Mastercard are often accepted in absolutely all business. Never mind if it is a hotel, restaurant or just a little shop or supermarkets.
They will, usually, ask a minimum payment (this is... for a little purchase they will ask to pay in cash, they will accept cards only for higher purchases because they will have to pay a fee for any card).
Ask to your bank about using the card in Spain (fees because abroad, rates if necessary to exchange, etc...)
You will be able to use them in cash dispensers. Just introduce it and write the amount of money you want. Ask to your bank about fees if asking money in cash dispensers (take care that... it could be cheaper and safer than carrying foreing money in cash and later asking for a currency exchange)
In a lot of cash dispensers, when they will notice that it is a foreing card, the first thing they will do is to ask about the language you want to use there. That will make your operation easier.
Almost all cash dispensers will give 10, 20 and 50 euro banknotes. If you want to have a higher banknote (for instance 100), you will have to enter inside the bank and ask for a change (2x50 = 100, just that)
I have to point that I have seen few places in Zaragoza where American Express or Diners Club are accepted. I have seen them... but they are not usually accepted. Take care about it.