What documents do you need to register as autonomo?
Updated: May 2026. To register as autónomo, you need documents for two separate filings: one with Hacienda (Tax Agency) and one with Seguridad Social (RETA). Below is the exact checklist for each, what changes if you are a foreigner, and how to do it online without going to an office. The single most common mistake: registering with RETA after the AEAT start date, which forfeits the €87.6 Tarifa Plana for this attempt. Sits alongside the freelancer registration pillar and the parent autónomo guide.
Quick answer
You need three things ready before you touch any form:
Identity: DNI (Spanish nationals) or NIE/TIE (foreigners), valid.
Spanish IBAN: for the Social Security cuota auto-debit.
Digital certificate or Cl@ve PIN: to file online.
Then you file in this order: Modelo 037 at AEAT first, then RETA at Seguridad Social the same day. Total time online: about 30 minutes. Cost: €0 to register, then €87.6/month cuota for the first 12 months under Tarifa Plana.
Before you start
Decide three things in advance, because the forms ask for them on the spot:
Your IAE activity code (epígrafe). The official catalogue of professions. Look up your trade on AEAT's epígrafe finder before filing. Common codes: 763 freelance technical services, 722 software and IT, 741 accounting, 826 teachers, 841 designers.
Your start date. Today or up to 60 days ahead. This date is binding for the RETA filing that follows.
Your VAT regime. Régimen general for most professionals. Mark VAT-exempt only if your activity qualifies (medical, education, financial). More in the Spanish VAT number guide.
For most autónomos, Modelo 037 is enough. It is the simplified version and covers freelancers, consultants, designers, developers, trainers, and most service businesses.
Use Modelo 036 if any of these apply:
You import or export goods.
You apply for VAT exemption on intra-EU transactions.
You are registering a partnership or a company (not a sole trader).
You opt into a special tax regime (recargo de equivalencia, modulos, etc.).
If you are not sure, use 037.
What you need:
DNI (Spanish nationals) or NIE (foreigners): your tax identification number. Must be valid and not expired.
Modelo 037 (or 036 if applicable). You fill it in during the registration session, not in advance.
IAE activity code: selected during the form. Have it ready.
Business address: your home address is fine for most service businesses.
Start date: today or up to 60 days ahead.
You can register in-person at any AEAT office or online at sede.agenciatributaria.gob.es using a digital certificate or Cl@ve PIN.
Stamped Modelo 037 or 036: the PDF you saved from AEAT, showing your activity code and start date.
Spanish bank IBAN: the cuota is auto-debited monthly. A SEPA-zone IBAN also works, but a Spanish account is faster to set up.
Contribution base selection: declare your estimated monthly net income for the year. This sets your cuota. You can adjust the band up to six times a year. Detail in autónomo costs.
Mutua selection: the insurer that covers sick leave and accidents. You pick one at registration. Asepeyo, Fremap, Fraternidad, Mutua Universal all offer comparable coverage; default to one.
Tarifa Plana confirmation: tick the reduced-rate box if you have not been autónomo in the last 2 years (or 3 years if you previously claimed the discount). Detail in the reduced rate guide.
EU citizens (German, French, Italian, etc.): you can show your EU national ID or passport at offices, but you still need an NIE to register and to invoice. Get it at a Comisaría de Policía or through the consulate before you move. The NIE is the tax ID that appears on every invoice you issue.
Non-EU citizens: you need a TIE (Tarjeta de Identidad de Extranjero, the residency card) plus a valid work authorisation that permits self-employment. Permits that qualify: cuenta propia work permit, Digital Nomad Visa, long-stay visa with work authorisation, or family reunification with work rights. Detail in can a foreigner register as autónomo.
Without the right residency and work authorisation, you cannot legally register as autónomo. Tourist visas and student permits do not qualify.
Online registration: what you need extra
To register without going to an office, you need one of two digital identities:
Certificado digital: a digital ID from the FNMT (Fábrica Nacional de Moneda y Timbre). Free. Valid for 4 years. Apply at sede.fnmt.gob.es, then verify your identity in-person once at any AEAT office or Registro Civil. After verification, download and install the .pfx file in your browser. Step-by-step in how to obtain a digital certificate.
Cl@ve PIN: a government identity system that logs you in with an SMS code. Easier to set up. Works for most autónomo procedures, though a few advanced filings still require the digital certificate.
Both are free. If you plan to be autónomo long-term, get the digital certificate. You will use it for quarterly tax filings (Modelo 303, 130), Social Security changes, electronic notifications via DEHú, and official correspondence for years.
Full checklist
AEAT (Tax Agency)
DNI or NIE (valid).
Modelo 037 (or 036 if your situation is complex).
IAE activity code selected.
Business start date confirmed.
Home or business address.
RETA (Social Security)
DNI or NIE.
Stamped Modelo 037/036 PDF from AEAT.
Spanish or SEPA-zone IBAN.
Estimated monthly net income for the contribution base.
Mutua selected.
Tarifa Plana box ticked (if eligible).
For online registration (either step)
Digital certificate (certificado digital) or Cl@ve PIN active.
For foreigners
NIE (EU citizens: Comisaría de Policía or consulate).
TIE plus valid self-employment work authorisation (non-EU citizens).
Common mistakes
Filing RETA after the AEAT start date. Forfeits the €87.6 Tarifa Plana for this registration. File AEAT first, then RETA the same day, never later.
Expired NIE or DNI. A document past its expiry date will be rejected at the counter. Renew before you file.
Wrong IAE epígrafe. A mismatched activity code can trigger AEAT questions years later. Look it up before filing.
Backdating the start date. Saying you started before today triggers a small fine. Forward-dating up to 60 days is fine; backdating is not.
No Spanish IBAN ready. Without one the cuota cannot auto-debit and Seguridad Social will start chasing you within a month.
Tourist or student visa as a non-EU citizen. Neither permits self-employment. You will be rejected.
Important timing notes
Two timing rules trip people up:
Your AEAT start date should match the date you actually begin invoicing or marketing services. Backdating triggers a small fine. Forward-dating up to 60 days delays your VAT obligations until that date.
RETA must be filed on the same day as AEAT or earlier (up to 60 days before the declared start date). Never after. Filing RETA after the AEAT start date permanently forfeits Tarifa Plana for this registration.
Register before you invoice. In-person, the whole flow takes one to two days. Online, it can be done in a single morning.
What happens after you register
Once both registrations are accepted, you are officially autónomo. From there:
Your monthly Social Security cuota debits at the end of the month. €87.6/month under Tarifa Plana for the first 12 months, then €205 to €605 by income band (2026 levels). Frozen at 2025 with MEI uplift to 0.9%.
Your first quarterly returns cover the quarter you registered in. Modelo 303 for VAT, Modelo 130 for IRPF if 70%+ of your invoices are not under retención. Math at how to calculate IRPF trimestral.
Your first annual return (Modelo 100) falls in April–June of the next year.
VeriFactu certified invoicing becomes mandatory for autónomos on 1 July 2027. Pick a Verifactu-ready tool now.
FAQ
Do I need a digital certificate to register? No, you can register in-person at any AEAT and TGSS office. Online registration needs either a digital certificate or Cl@ve PIN.
Can I use a foreign IBAN for the cuota? SEPA-zone IBANs work, but a Spanish IBAN clears faster and avoids edge-case rejections.
How long does the registration take? Online: about 30 minutes if your documents and digital identity are ready. In-person: usually one to two days end-to-end.
Can I register without a fixed business address? Your home address works for most service businesses. A formal commercial premises is only needed for retail or trades that require licensing.
What if I make a mistake on Modelo 037? You can file a correction (declaración complementaria) afterwards. Easier to get it right the first time, especially the IAE code and start date.
Do I need to register a trade name? No, you invoice under your own name and NIF/NIE. A trade name is optional.
Summary
Six items in your folder, two filings on the same day, one timing rule. DNI or NIE, Modelo 037, IAE code, IBAN, mutua choice, contribution base. AEAT first, RETA same day, Tarifa Plana ticked. Done in order, you are legally registered as autónomo in under an hour and pay €87.6 cuota for your first year. If you would rather not deal with the paperwork, renn registers your autónomo online end-to-end and most clients are live within 24 hours.
