The process to register a Spanish branch usually takes 2 to 3 weeks  (once the documents have been filed with the Commercial Registry).  There is a requirement for the branch to have a representative. They do not have to be a citizen of or resident in Spain, but non-residents need to obtain a NIE. If a non-Spanish resident is appointed as Representative, then the branch must appoint a Spanish resident (individual or entity) as tax representative. No bank account is required.