Member states can introduce an exception to the B2B rule according to the place where the services have been used and enjoyed. This exception may be introduced to avoid double taxation (positive use and enjoyment rules) or avoid non-taxation (negative use and enjoyment rules) or both.
Spain has introduced the negative use and enjoyment, hence attracting the place of supply to Spain if the customer is established outside the EU but the actual use of the service is connected to Spain. The following services are in scope: transfer of copyrights and similar services, supply of staff, financial and banking services, data processing, consultancy services, advertising services, hiring of moveable property and access to electricity and gas.
Spain has not introduced the positive use and enjoyment rules which deviate the place of supply to a non-EU country where the services are used and enjoyed in that non-EU country. In these scenarios, there is indeed a risk of double taxation in Spain.