How to register as an autónomo in Spain: a step-by-step guide

You can register as an autónomo (self-employed) yourself in a single evening: three filings, two authorities and one date that runs through them all. You need a digital certificate or Cl@ve, an NIE, a Spanish bank account and activity codes. None of the steps carries a fee.

Below is the route field by field: what to tick in modelo 036 page by page, how to answer the Importass wizard when registering (alta) in RETA, how much will be debited in the first year and what starts immediately after registration.

Who can apply and in what order

Anyone of legal age with an NIE and the right to work on a cuenta propia (self-employed) basis can apply: EU citizens and holders of a residence permit that allows self-employment — digital nomad, cuenta propia, arraigo and others. A residence status that does not allow you to work for yourself makes the whole procedure pointless; what each ground allows is explained in our article on cuenta propia.

There are two authorities, and both must be notified before you start your activity.

• Agencia Tributaria (Hacienda, the tax agency) — modelo 036, before the first invoice you issue or the first business expense.
• Seguridad Social (TGSS) — alta in RETA (the self-employed scheme). You can apply in advance, but no earlier than 60 days before the start date. Backdated applications are allowed, but you then lose the reduced tarifa plana (flat rate).

The order: modelo 036 first, then RETA. And the key thing linking both filings: they must state the same start date of activity. This parameter runs through the whole procedure — a mismatch triggers a requerimiento (formal request) and may cost you the reduced rate.

What to prepare in advance

What	Why
Certificado digital or Cl@ve permanente	logging in to the AEAT and Seguridad Social portals, signing the forms
NIE	your identifier on every form — how to get one is explained in our guide to the NIE in Spain
A Spanish bank account	contributions are collected only by direct debit (domiciliación); the bank must be on the TGSS list of colaboradores — the big banks qualify
Referencia catastral	a mandatory field in modelo 036, found by address on the cadastre portal
CNAE and IAE codes	one for each authority, see the next section

Two classifications, and they are not the same thing

Hacienda and Seguridad Social use different code lists, and there is no one-to-one match between them. You choose a code in each separately.

Authority	Classification	Example: software developer
Seguridad Social (RETA)	CNAE-2025	62.10 — actividades de programación informática
Agencia Tributaria (036)	IAE, epígrafes	763 — programadores y analistas de informática

This is where almost all guides are out of date, including English-language ones. The classification has changed: Real Decreto 10/2025 approved CNAE-2025, and the Seguridad Social form accepts only that. The full structure with explanatory notes and correspondence tables to the old codes is published by INE. Codes from the 2009 list — such as 6201, popular in guides — are no longer valid.

Related IAE options for the same profession: 762 — doctores e ingenieros en informática, 764 — diplomados en informática, 845 — explotación electrónica por cuenta de terceros. The last one is no longer a professional but a business activity, and the retenciones (withholding) rules there are different. The choice is determined by the work you actually do, not by convenience.

Step 1. Social Security number (NUSS)

You need it if you do not have a number yet. If you have worked in Spain as an employee, you already have one and can skip this step.

1. In the Importass portal: Altas, bajas y modificaciones → Solicitar el número de la Seguridad Social.
2. Log in with a certificate or Cl@ve.
3. Four screens: personal details, address, contact details, confirmation.
4. Consent to data processing and signature.

The number is assigned immediately, and a PDF with it stays in your account. It takes about five minutes.

Step 2. Modelo 036 at Hacienda

It is filed in the AEAT online office, procedure G322. The form has many pages, navigated by tabs at the top. It takes 20–30 minutes. When asked whether to fill in the simplified version, answer “no”: the simplified mode does not offer ROI and some settings, and you would later have to file a modificación.

Page 1 — reason for filing

Field [111] Alta — tick it. Below is the Lugar, fecha y firma block: city, date, “Firma en calidad de” → Interesado, surname and first name.

Page 2A — who you are and where

• [A1] — “Sí, art. 9.1 LIRPF”: confirmation of tax residence.
• [A2] — nationality, [A3B] — the date from which you are resident.
• [A29] and [A26] — phone and email for AEAT notifications, both with the Alta box ticked. Requerimientos will be sent here, so the contact details must be in use.
• Domicilio — via “Buscar dirección” by postcode and street, then complete fields [A13]–[A23].
• [A30] — referencia catastral.

Page 4 — activity codes and place of work

“Añadir registro” → “Buscador de actividades”, find the epígrafe by number or keyword. Next comes the place of activity, and here there is a fork that affects your money:

• not tied to specific premises — “La actividad se desarrolla fuera de un local determinado”: municipality and start date;
• working from home or an office — “en un local determinado”: Superficie in square metres and Grado de afectación — the share used for work. An 80 m² flat with a 10 m² work room → 80 and 12.5.

This share is the basis for deducting part of your housing costs: 30% of the afectación share of utility bills is deductible (art. 30.2.5ª LIRPF). A field many people fill in at random is actually worth money every year.

Page 5 — IVA and ROI

• [500] — Sí, activity within the territory where IVA (VAT) applies; [501] — No, not fully exempt.
• [502] and [503] — tick and start date of activity for IVA purposes.
• [510] and [512] — Alta in the régimen general and date.
• [582], [583], [584] — Alta and date: application for inclusion in the ROI, the Registro de Operadores Intracomunitarios (register of intra-EU operators). What this number gives you, how to check someone else’s and what to file afterwards is covered in our article on the VAT number.

ROI is essential for working with EU clients: only with a number in VIES can you invoice services to European companies without IVA under the reverse charge mechanism. Without ROI you will have to charge 21%, which clients generally refuse to pay. The AEAT confirms inclusion separately, sometimes after a check.

Page 6 — IRPF

[600] and [602] — Alta and date. [609] and [650] — inclusion in estimación directa simplificada and date. This is the standard regime for turnover up to €600,000: accounting based on actual income and expenses plus 5% for “hard-to-prove expenses”, capped at €2,000 a year.

Page 7 — retenciones

Fill this in only if you will be paying other self-employed professionals in Spain: their invoices carry IRPF withholding (retención), which you must withhold and pay over. [701] and [721] — Alta and date; this adds modelo 111 every quarter and modelo 190 at year end. If you do not plan such payments, skip the page.

Submitting: “Firmar y Enviar”, then tick “Conforme” in the window. A PDF of the submitted return will open — save it: your bank will need it, and you will use it to check the data when registering in RETA.

Step 3. Alta in RETA

In the Importass portal: Altas, bajas y modificaciones → Alta en trabajo autónomo → Solicitar alta. A twelve-screen wizard, about 15 minutes. What it asks:

1. Start date of activity — the same as in modelo 036.
2. Start date of contributions. If you register other than on the first of the month, you can pay either only for the remaining days of the month or for the full month. The second option slightly increases your contribution record but costs money.
3. Type of activity — “Voy a trabajar por mi cuenta propia”.
4. Activity — CNAE-2025 code. You can enter several, but it is easier to start with one and add the others later through a modificación.
5. Professional association — “No es mi caso” if you are not a member.
6. Address of the activity.
7. Expected net income. For the first application a realistic estimate is enough; the figure is adjusted after 12 months. With the tarifa plana, income does not affect the contribution in the first year.
8. Contribution base. For the tarifa plana — the minimum base: €960.60 in 2026.
9. Tarifa plana — tick it. Conditions: no alta in RETA in the last 2 years (3 if you have already used the reduction), not an autónomo colaborador (family collaborator), no debts to the TGSS or AEAT.
10. Pluriactividad — the first option, if you also have an employment contract in Spain.
11. Mutua colaboradora — any; it covers sick leave and accidents and can be changed later.
12. IBAN for contribution debits.

There is just one trap in this wizard, and it is an expensive one. The option “Trabajo con un cliente principal” does not mean “I have one client”. It is TRADE status (autónomo económicamente dependiente, economically dependent self-employed worker) with a mandatory registered contract and a separate regime. An accidental tick puts you into it. Do not choose it.

The decision “Alta en RETA. Resolución” arrives in your Importass account within a few days, with a notification also sent by email.

How much will be debited

Component	Amount	What it is
Tarifa plana	€80	the first 12 months, regardless of income
MEI	+ €8.64	0.9% of the €960.60 base in 2026
Total per month	€88.64	debited from the first month

The MEI — Mecanismo de Equidad Intergeneracional (intergenerational equity mechanism) — rises by 0.1 percentage points a year to 1.2% in 2029.

• An extension for another 12 months is possible if your net income in the first year is below the SMI (minimum wage). The application must be made before the end of the first year — the reduction does not extend automatically.
• Without the reduction, the contribution is calculated on a scale according to expected income: in 2026 roughly €200 to €590 a month. At the end of the year the TGSS compares declared income with actual income from Hacienda data and charges or refunds the difference.
• Cuota cero. Madrid, Andalusia, the Canary Islands, Galicia, Murcia, the Balearic Islands and several other autonomous communities refund the €80 paid for the first, and sometimes the second, year. This is a separate application to the regional authority after the alta; the monthly debits continue as normal in the meantime.

It is worth knowing about late payment in advance. Collection is by direct debit only. If there is not enough money in the account, a recargo (surcharge) is added for the month in arrears, and that month’s contribution is charged at the full rate rather than the tarifa plana. The reduction resumes once the debt is paid, but the lost month is not compensated.

The amount of the reduced contribution, incidentally, is not fixed forever: the €80 was set by a transitional provision of RD-ley 13/2022 for 2023–2025, and from 2026 it is set each year by the state budget law.

What starts immediately after registration

• VIES. Check your NIF in the VIES database: until your number appears there, you cannot invoice EU clients without IVA.
• Invoices. Mandatory details: number and date, your NIF and address, client details, description, taxable base, IVA rate and amount — or a reference to inversión del sujeto pasivo (reverse charge) for the EU and “operación no sujeta” for non-EU countries.
• Verifactu. From 1 July 2027 invoices must be issued through Verifactu-compatible software; until then it is voluntary. The deadline was set by RDL 15/2025.
• Quarterly — by 20 April, July and October and 30 January: modelo 130 (IRPF advance payment) and 303 (IVA). For EU transactions, also 349.
• Annually — 390 (IVA summary, January), 347 (counterparties over €3,005.06 a year, February), Renta (income tax return, April–June).
• Accounting books — for income, expenses and investment assets. The format is free, but the data must match your returns.
• After 12 months — review your contribution base against your actual income (you can change it up to six times a year) and, if your income is low, apply to extend the tarifa plana.

What exactly is paid next and when is covered in our breakdown of taxes and contributions for autónomos. A general overview of the status is in the article Autónomo in Spain.

Six mistakes that most often need correcting

1. Different start dates in 036 and RETA — a requerimiento and the risk of losing the tarifa plana.
2. An old CNAE code — the form accepts only CNAE-2025; codes from the 2009 list, such as 6201, are not valid.
3. The simplified 036 mode — no ROI and a reduced set of fields; you would later have to file a modificación.
4. Missing ROI — 21% IVA on invoices to European clients, who generally refuse to pay it.
5. Choosing “cliente principal” — ending up in the TRADE regime by accident.
6. An empty account on debit day — losing the reduction for the month plus a recargo.

FAQ

How long does autónomo registration take?

About an hour online: five minutes for the Social Security number, 20–30 minutes for modelo 036 and about 15 minutes for the alta in RETA. The RETA decision arrives in your account within a few days.

How much does it cost to register as an autónomo?

Registration itself is free — there is no fee at either Hacienda or Seguridad Social. You start paying from the following month: with the reduced rate, €88.64 a month including the MEI.

Which comes first — 036 or RETA?

First modelo 036, then the alta in RETA. Both filings state the same start date of activity; a mismatch triggers a requerimiento and may cost you the reduced rate.

Can you register retroactively?

Backdated registration is allowed, but you lose the tarifa plana. You can register in advance no more than 60 days before the start date of activity.

Do you need a gestor?

Not for the registration itself — the whole route can be done online with a digital certificate. A gestor pays off later, for quarterly filings and for choosing codes if your activity is unusual. Who a gestor is and what they do is explained in our article on the gestor.

Which activity code should a software developer choose?

For Seguridad Social, CNAE-2025 62.10; for Hacienda, IAE epígrafe 763. Related IAE options are 762, 764 and 845, and the last one is already a business activity with different retenciones rules. The choice is determined by the work you actually do.