Becoming self-employed here is technically a two-step process: first, you register with the Tax Agency (AEAT), and then with Social Security (RETA, via Importass). Sounds simple enough, right? Well… this is Spain, so there are always a few forms, deadlines, and tiny-but-important details lurking in the fine print.
This guide walks you through exactly what to file, when to file it, what it costs, and what your very first tax tasks will look like once you’re officially “autónomo.” You can even pre-file up to 60 days before your start date, but make sure both registrations are done by the time you actually begin working (because, yes, even bureaucracy runs on deadlines).
Q&A
Do I need to register twice?
Yes. First with AEAT (Tax Agency), then with Social Security. Both must be active before you issue invoices.
Which form do I use at AEAT?
Use model 036 through “Censos WEB” (AEAT’s online census service) to declare your activity, choose your VAT/IRPF regimes, and select your IAE epígrafe (your activity code).
Do I pay the IAE tax?
Most freelancers do not pay IAE until they exceed €1,000,000 in annual turnover. You still must choose and register an IAE epígrafe.
Is there a flat monthly Social Security fee?
New freelancers can get the €80 “tarifa plana” for 12 months. You can request a 12-month extension if your annual net income stays below the minimum wage.
How to register as a freelancer in Spain
The takeaway: three moves - eID ready → AEAT model 036 → Social Security (Importass).
- Get your digital certificate (FNMT) or Cl@ve (secure login) so you can file online.
- File model 036 to tell AEAT who you are, what you do, and your tax regimes.
- File your Social Security “alta” in Importass, choose your contribution base, pick a Mutua (the insurer for sick leave/accidents), and set your bank account. Do all this before or on the day you start.
Prerequisites and documents
The takeaway: sort IDs and access first so filing takes minutes, not hours.
Have this ready: DNI or NIE, your tax ID (NIF linked to your NIE), a Spanish IBAN, a mobile and email for notices, your business address, your planned start date, and your IAE epígrafe (activity code). Set up a digital certificate or Cl@ve to access AEAT and Importass online.
Step 1 - Get your digital certificate (FNMT) or Cl@ve (secure login)
Before you can register online with AEAT or Social Security, you need a digital ID.
You can choose between:
- Digital certificate (FNMT): a small file you install on your computer or phone to identify yourself on official websites. You request it online, verify your identity at a registration office (or through video identification if eligible), and then download it. It’s valid for 4 years and works for all public platforms (AEAT, TGSS, DGT, etc.). In renn, we can also request it for you.
- Cl@ve: a simpler login system that lets you access AEAT and Seguridad Social services with a PIN or QR from your phone. You can register online with a digital certificate, or in person at a registration office, or by requesting a code sent by post.
Both are free. The FNMT certificate offers broader use (needed for electronic signing), while Cl@ve is easier for everyday logins.
Once you have one of them, you can complete your freelancer registration fully online without visiting any office.
Step 2 - AEAT registration (model 036): pick your IAE epígrafe and tax regimes
The takeaway: model 036 via Censos WEB is your tax “on switch”.
Enter Censos WEB and file model 036. In one form you will:
- Declare your activity start date.
- Choose your IAE epígrafe (activity code).
- Pick your VAT (IVA) and IRPF regimes.
You must do this before you issue any invoice.
IAE epígrafe (activity code)
It’s the label for your job. Designer, developer, photographer, café owner - each has a code. Most freelancers won’t pay IAE until they pass €1,000,000 turnover, but the code is still mandatory for registration.
Let´s imagine you want to register as an IT developer 👩🏻💻: in "Buscador de actividades" you´d type 763 and press "Seleccionar".
Once you´ve already chosen your activity you have to select where you carry out your activity:
VAT (IVA) regime
- General regime: you add VAT to invoices and deduct VAT on business expenses.
- Special cases: for example, “recargo de equivalencia” (a retail surcharge where the supplier charges extra and the retailer doesn’t file VAT returns).
Most service freelancers use the general regime.
IRPF method
- Direct estimation (simplified): the default for most freelancers. You report real income and real expenses.
- Modules (objective estimation): only for certain activities and limits; it uses fixed amounts instead of your real numbers.
If unsure, contact us.
When you finish filling the information press "Validate tax record" and then "Sign and send".
Once sent, congrats! you are one step closer 🧡.
You can read more about this here.
Step 3 - Social Security registration (Importass/RETA).
Open Importass and file Alta en trabajo autónomo.
You will:
- Set your start date and address.
- Choose a contribution base within your income bracket.
- Pick a MUTUA (for accidents, etc)
- Last step: enter your IBAN for direct debit and review all your information before submitting the request.
You can read more about this here.
Costs and timelines
The takeaway: filing is instant online; monthly cost depends on your income and base.
- Social Security fee: varies by your chosen base and income bracket; many new freelancers pay the €80 flat rate at first.
- AEAT filing: free.
- Digital certificate: free.
- Timing: once you have eID access, model 036 and Importass can be done in one sitting. With CIRCE/PAE, the whole process often finishes in under 24 hours.
Make it painless
renn can set up your autónomo account, fetch expenses from your bank, email, and WhatsApp, apply the right VAT/IRPF rules, issue verifactu-ready invoices, show real-time VAT and IRPF, and have accountants review and file your returns on time.
Bottom line
Get your eID, file model 036 in AEAT, then file your alta in Importass with a sensible base and a Mutua. Do it before or on your first day, use the €80 flat rate if eligible, and set your quarterly VAT and IRPF reminders now.
