Census registration comes before you start
The Tax Agency asks for the census registration before the activity starts. It is not a filing you leave until after the first job is invoiced.
Before the activity starts
The census registration is filed before the start. If you wait for the first invoice, the date is already late against what the Tax Agency treats as starting. The form is modelo 036 or, if your case fits, modelo 037.
- The census is filed before you start.
- Modelo 036 or, if it fits, 037.
- The first invoice does not replace the registration.
What counts as starting
The activity starts when you deliver goods, provide services, buy, collect, pay, or hire staff for that activity. You do not have to have been paid by the client. A purchase or a payment tied to the activity can already be the start.
Common questions
Can I register on the same day I invoice?
The census registration has to be filed before the activity starts. Invoicing, buying, collecting, paying, or hiring for that activity is already starting it.
Does hiring someone count as starting?
Yes, if you hire staff for that activity. Delivering goods, providing services, buying, collecting, or paying for it also counts.
Official sources
Informational text reviewed on 26 September 2026. It is not tax advice and does not replace the Spanish Tax Agency or your accountant. Deadlines, rates, and forms can change.