Registering in the VIES in Spain
Can I apply for an European VAT number if I operate in Spain through a virtual office ?
A virtual office will not let you qualify to get an EU VAT number. You will not be registered in the VIES as a taxable person. In other words, if you intend to buy or sell in other EU countries, the Spanish Tax Office require that you have a physical office with at least one employee (or the Director of the company).