Use of a Sky box outside the UK
If you have paid for a Sky box, and that box is not part of any Sky UK discount installation agreement, or subject to the 12 month new installation discount agreement telephone connection stipulation, or part of Sky multiroom, then the Sky box is yours and not Skys. You can do with it what you want and take it wherever you want. The are no restrictions on "non discounted" Sky boxes in or out of the UK, as they are not Skys property. They are your property.
There are restrictions on those boxes that are discounted by Sky, via their discounted UK installations, and on the cards themselves. But no restrictions on buying a nondiscounted Sky box.
Sky (UK, Italy, Germany etc) are one of the few that actually allow you to own your Sky box. Other broadcsaters, like Spains D+ rent the boxes, and there is a small charge in your monthly sub for this. So D+ boxes remain D+, not the clients. Which is why D+ receivers are hard to come by in other countries.