According to art. 5 of RD 557/2011, those non EU citizens who want to enter Spain while applying for extension of his residence permit or applying for the new Id card for Foreigners (TIE), will need to apply for a return permit.
You can also contact:
The return permit will issued by the National Police Stations. If you are living in Barcelona City you will need to apply for an appointment at the following this web site.
For more information see:
International Support Service (ISS)
Builiding Biblioteca de Comunicació i Hemeroteca General, Plaça Cívica
Campus de Bellaterra
Tel. + 34 93 581 22 10
Fax + 34 93 586 80 25
Monday to Friday from 9:30am to 3pm
Thursday from 9.30 to 16.30