In the binding tax ruling V1361-16 the Spanish Tax Authorities analyse the situation of a non-resident entity operating in Spain both through a permanent establishment (PE) and by performing a different business activity without the intervention of the Spanish PE.
The criterion followed by the tax ruling is the non-resident entity needing to obtain two different tax numbers from the Spanish Tax Authorities: one number (starting with the letter W) for the PE, and another one (starting with the letter N) for their activities performed without the intervention of the PE.
Also, the company is required to file all relevant VAT returns for each tax number for the Spanish VAT amounts to be deducted (or refunded).