A Sky TV viewing card will work any Sky TV receiver for the "6 mix" channel packages. This is useful if you come back and forth to Spain annd bring your Sky card from your UK home to your Spanish home, as it mean you can get some of the Sky channels you subscribe to.

However, the Sky TV premium channels, like Sky Sports and Sky Movies, are Sky box specific and will only work on their originally activated Sky digibox. If you access these channels on your "second" Sky box you will see a message saying that “This is the wrong card for this set top box”.

It is against the terms and conditions of your Sky contract to use the Sky viewing card outside the UK and ROI. I am unsure if the term "it is illegal to use a Sky card in Spain" is correct or not, as the term illegal means that the Police can arrest and prosectue you for using a Sky card in Spain, which to my knowledge has not yet happened. Should Sky find out that the card is not being used in the UK, at the UK address your card is regitered to, then they will cancel the card.