Tax guide · Procedures
How to register as self-employed in Spain: complete guide step by step
Every procedure explained: choosing your IAE heading, census registration with the AEAT and RETA registration with Social Security.
By Jacobo Quesada, practising tax adviser and co-founder of TributAI · Updated on
What registering as self-employed involves
Being self-employed in Spain means working for yourself. To do so legally you must complete two main procedures: the census registration with the AEAT (to declare that you are starting an economic activity) and the registration in the RETA (Special Scheme for Self-Employed Workers) with Social Security (to contribute and have benefit coverage).
Both procedures are independent but complementary. Starting to invoice without being registered with both bodies can lead to tax penalties and Social Security surcharges.
The steps
The steps to register as self-employed
Choose your IAE heading and CNAE
Identify the activity you are going to carry out. The IAE heading determines your tax obligations; the CNAE is used in official statistics and in some Social Security procedures.
Census registration with the AEAT — Form 036 or 037
File Form 036 (general census) or Form 037 (simplified version) with the AEAT to declare the start of activity, the applicable VAT and income tax regime and the details of the business. This procedure comes first and is essential.
RETA registration — Social Security
Process your registration in the Special Scheme for Self-Employed Workers (RETA) with Social Security using form TA.0521. State whether you are applying for the flat rate at the same time.
Set up the direct debit for the RETA fee
Give your IBAN when registering in the RETA so the monthly fee is charged automatically. Social Security only accepts bank direct debit for self-employed people.
AEAT and Social Security: key differences
| Body | Procedure | What it is for |
|---|---|---|
| AEAT | Form 036 / 037 | Census registration: declares the start of activity, the VAT and income tax regime and the IAE heading |
| TGSS / Social Security | TA.0521 | RETA registration: monthly contribution, benefit coverage (incapacity, cessation, retirement) |
Applying for the flat rate from day one
If it is the first time you register as self-employed (or more than 2 years have passed since your last deregistration), you are entitled to the flat rate: a reduced fee of €80/month for the first 12 months.
To benefit, you must tick the relevant box when registering in the RETA (form TA.0521). It cannot be requested afterwards. The flat rate can be extended by another 12 months if net income in the first year is below the current Minimum Interprofessional Wage.
→ Complete guide to the self-employed flat rateFrequently asked questions
Frequently asked questions
What documents do I need to register as self-employed?+
You need: a valid DNI or NIE, a bank account number (IBAN) to set up the direct debit for the RETA fee, and the details of your activity (heading in the National Classification of Economic Activities, CNAE, and in the Economic Activities Tax, IAE). If you are going to work from premises, also the details of the premises.
How long do the registration procedures take?+
Census registration with the AEAT (Form 036 or 037) is immediate if done online through the e-office or through an Entrepreneur Service Point (PAE). RETA registration with Social Security is also immediate online, although at an office it can take 1 or 2 working days. In total, the whole process can be completed in under an hour if done online.
When should I register as self-employed?+
Census registration with the AEAT must be done before the economic activity starts. RETA registration must coincide with the start date of the activity, or the day before if you want the flat rate to apply from day one. Starting the activity without being registered can lead to AEAT penalties and Social Security surcharges.
What is the IAE heading and how do I choose the right one?+
The Economic Activities Tax (IAE) heading classifies your economic activity. It is divided into three sections: First (business activities), Second (professional) and Third (artistic). Choosing the right heading matters because it determines your tax obligations and the type of activity before the AEAT. If in doubt, a PAE or a tax adviser can help you choose.
Is it compulsory to register for the IAE?+
Self-employed people with annual turnover under €1,000,000 are exempt from paying the IAE (Art. 82.1.c of the Consolidated Text of the Local Taxation Law), although they must still include the heading in Form 036/037 for the census declaration. Only those who exceed that threshold pay the municipal IAE.
Online self-employed registration with TributAI
Our Punto PAE processes your registration through CIRCE (the official one-stop shop of the Ministry of Industry), reviews and signs it within 24 business hours; confirmation from the AEAT and Social Security comes afterwards and depends on them. No digital certificate or office queues.
This guide is for guidance only and is not binding tax or employment advice. Rules can change; always check the AEAT e-office, Social Security or an Entrepreneur Service Point (PAE) for your specific situation. This is an informative translation: the Spanish version prevails.