This review is not just for this Telefonica branch, but for all. As a traveller, if you are…read morelooking for a data plan SIM while you travel in Spain, do yourself a favor and get it from Vodafone. Telefonica has the most horrible and poor service I have ever experienced. 1. To buy the SIM card, we had to sign several forms, provide emails, photocopy passports. At Vodafone, you just pay for you SIM card and go. 2. At Telefonica, the service doesn't activate instantly. You have to wait for about a day. They didn't tell us this before we bought it, and wouldn't refund us afterwards. They said we just had to wait and to "trust them". They kept saying it was "impossible" to provide a refund. At Vodafone, your service will activate almost instantly. 3. Service is extremely poor and slow. Even in downtown Madrid, I would lose connection often. Vodafone's coverage is excellent. 4. The entire experience took almost an hr at Telefonica. At Vodafone, we were in and out in 5 min... literally. While Telefonica may have a cheaper data plan for travelers, trust me, it is not worth it. Pay a few dollars more and go with Vodafone.