Traveller registration in Catalonia: the Mossos have no API (and what that means)

If you run accommodations in Catalonia and you got here looking for how to connect your system to the Mossos d’Esquadra, the short answer is an uncomfortable one: there is no way. There is no API, no web service, no endpoint. Traveller registration in Catalonia is filed by uploading a text file by hand on a web portal.

It is worth knowing before you quote for an integration, because this is not a case of documentation that is hard to find: the channel simply does not exist.

Only two regions go their own way

Since 2 December 2024, SES.Hospedajes (Ministry of the Interior) has been the single system for traveller registration in Spain, with two exceptions: the regions with their own police force competent in the matter.

That “rest” includes Galicia, Madrid, Andalusia, the Valencian Community, the Balearics, the Canaries and all the others. It is a common confusion to think every region has its own: no, only these two.

What the Mossos require

• Registering the establishment first, identifying yourself with idCAT Mòbil or a digital certificate.
• Your own username and password per establishment — there is no integrator or platform credential.
• Filing within 24 hours of the start of the stay.
• Keeping the information 3 years at the police’s disposal.
• Since December 2024, registering every guest, under-14s included, and also filing bookings and cancellations.

The file: a format inherited from 2003

There is a “bulk” route, but it is not what a developer expects. The official manual literally describes a person choosing a file in their browser: you generate a text file and upload it from the portal. The format comes from a 2003 resolution, predating all of this:

08043AAR02.001
08043AAR02.002
…
08043AAR02.999   → back to .001

Alphabetic values go in uppercase, unabbreviated, left-aligned and without odd characters in compound surnames.

And there is no history

This is the detail that most constrains any automation. The portal itself warns that it does not store the customers you send and that there is no history of the filings made by the establishment.

In other words: you cannot check afterwards what you sent or whether it was accepted. There is no per-traveller confirmation code as there is in SES. You upload the file, you see a message on screen, and the trail ends there — the obligation to keep the information rests entirely with you.

What options you have left

Generate the file and upload it yourself

This is the honest route. Your system produces the .txt in the right format and a person uploads it to the portal. It is not automatic, but it is reliable and it does not store anyone’s police credentials.

Automate the portal with a robot

Technically possible: an automated browser that signs in and uploads the file. In practice it has three serious problems worth facing head-on:

• You have to hold the username and password for each customer’s access to a police system.
• It breaks with any change to the portal, and it breaks silently.
• With no history, you cannot verify that the submission arrived. A failure can go unnoticed for weeks.

Wait

There is no public sign that the Mossos are going to publish a web service. Planning on the assumption that it will arrive soon is risky.

In short

Catalonia is, today, the most expensive integration in Spain for traveller registration, precisely because it is not an integration: it is a manual process with a twenty-year-old format. If your operation is mostly outside Catalonia and the Basque Country, automating with SES Hospedajes covers the rest of the country with a single piece of development.

And if you were looking for this for Galicia, Madrid, Andalusia or anywhere else: there there is a web service, and we cover it in how to integrate SES Hospedajes with your PMS.