How to submit a complaint to the Bank of Spain (Banco de España)
The first step is always filing a a complaint to your bank, as this is a mandatory requirement for the Bank of Spain, which consists on submitting a written claim to your bank's Customer Service Department. We do recommend that this is done by a Lawyer particularly if you are not a Spanish-speaker.
If once that complaint to your bank has been issued you do not agree with the decision or receive no reply as a consumer within one month - 15 working days in the case of payment services, whether as a consumer or firm - or two months, if you are not a consumer, then it's when you can approach the Banco de España.
The complaint to the Bank of Spain would consist on submitting a claim whether online (in Spanish) or in written (in Spanish) issued to the General Register of the Banco de España or by mail, addressed to:
Banco de España
Institutions Conduct Department
C/ Alcalá 48
It could also be presented via any of its branches in the Spanish Territory.