Originally Posted by
Spirou
For Switzerland, I can say from my experience that I only pay income taxes if the prices exceed ~75 EUR/100 USD for books. This seems to be valid for all different amazon domains I use (.com, .de, .fr, .co.uk). The reason is not the origin of the package probably, but how much "tax value" is in the box (and if the item is properly declared as "book"). Swiss border only seems to react if the tax value exceeds a certain amount, probably it's the same in spain. You could give your customs a phone call in order to find out how they handle these packages and which amounts or items are "tax free".