How to book at a Spanish consulate in the US
Spanish consulates use the Ministry of Foreign Affairs booking system, with one link per procedure on each office's website. It is not a single calendar: passports, the NIE and civil registry each have their own, and national visas are arranged by email.
And before anything else: the appointment is free. The New York consulate states explicitly that it authorizes no booking service outside its own website.
Two offices break the pattern. Boston books by email only, never by phone, and asks for 48 hours' notice to cancel. Chicago warns it cannot provide adequate telephone service and refers everything to its website and email.
How each office books
If there is no slot
Passport slots open every day at no fixed time, releasing a batch for the next available date. The consulate's own advice is to check at different hours and not repeat searches back to back, because the system locks you out for security.
If nothing opens, check two things first: that you are registered as a resident —without it there is no username— and that the office you are looking at is the one for your district. In California that depends on the county, not the state.
This site is an independent directory. consuladosespana.us is not the Spanish Embassy or any of its consulates, and it processes no documents.
We gather what exteriores.gob.es publishes and flag it when its own pages disagree. Confirm with the office before you go.