Modelo 036: registration in the census of entrepreneurs and professionals (AEAT)

What you need to have at hand

1. Cl@ve PIN or certificado digital/DNIe to sign.
2. DNI/NIE/NIF and, if you're a sociedad, administrator data and the escritura.
3. Start date of activity (realistic — the day you start invoicing).
4. Address for domicilio fiscal and, if relevant, the premises/workspace address.
5. Epígrafe IAE that fits what you do.
6. Bank account (IBAN) for refunds or direct debits.
7. If you will do intra-community operations, be clear why and how to justify the ROI.

Documentation

• Identification: DNI/NIE or NIF of the person or entity.
• Representation: authorisation and NIF of the representative if you don't sign yourself.
• Activity data: description, epígrafe IAE, premises address if any.
• Tax obligations: what you'll declare (IVA, IRPF/IS, retenciones) and the periodicity.
• Bank account: for refunds/direct debits.
• Supporting documents for ROI or special regimes if requested (contracts, quotes, website, etc.).

Step by step

1. Go to the Sede de la AEAT: Modelo 036 telematic (official link) and log in with Cl@ve or certificado.
2. Create an alta in the censo. Enter the start date and check your identification details.
3. Complete Domicilio fiscal and, if needed, a different notifications address.
4. In Actividades e IAE, add your main activity (and secondary ones if relevant) and the premises if any.
5. Define IVA (general regime or exempt if applicable, and periodicity), IRPF (estimación directa normal/simplificada) or IS if you're a sociedad, and the retenciones you'll apply (professionals, rent, payroll).
6. Tick ROI if you'll operate with the EU. Note: it's not activated immediately.
7. Review the summary, sign and submit. Download the receipt with CSV. If you requested ROI or special options, watch DEHú for requests.

Time-saving tips

• Make a list of models you'll need after registration: 303 (IVA), 130/131 (IRPF), 111/115 (retenciones). That avoids panicking in the first quarter.
• If you're unsure between 036 and 037, use 036 and avoid missing cases.
• Save the CSV from the receipt to your cloud and email it to yourself. They'll ask for it repeatedly.
• If the form throws weird errors, try Chrome or Edge and clear the cache. Often it's the browser, not you.

Common mistakes that can mess up the process

1. Putting a start date in the past and filing late: 200 € fine for censal out-of-time.
2. Not ticking retenciones when you'll hire professionals or rent an office: later you get a requirement and surcharges.
3. Requesting ROI without justification: they deny it and it blocks EU operations.
4. Choosing the wrong epígrafe IAE and activating obligations that don't apply: you'll need to change it with another 036.
5. Forgetting to report deregistration or changes within 1 month: another avoidable fine.