Registering for Social Security in Spain as an Autónomo
A comprehensive step-by-step guide for obtaining your RETA registration
Becoming self-employed (autónomo) in Spain involves two key registrations: first with the tax authority (Agencia Tributaria/Hacienda) and then with Social Security. This guide focuses on the complete process of registering for Social Security as an autónomo, officially known as the alta in the Régimen Especial de Trabajadores Autónomos (RETA).
We'll cover why this registration is mandatory, what you need beforehand, the exact steps to register (online or in person), what to expect after registering, and common pitfalls to avoid. The goal is to provide clear, detailed instructions so an English-speaking expat can handle the process without a gestor (administrator).
1. Why Social Security Registration is Mandatory
Legal Requirement
In Spain, anyone conducting regular economic activity on a self-employed basis must register under RETA. This is not optional – even if your earnings are low, if the work is habitual you are expected to join the autónomo system. By law, the Social Security registration should be done before or on the same day you start your business activity.
Access to Benefits
Registering in RETA secures your access to Spain's public social security benefits as a self-employed worker. Once registered and contributing, you will be entitled to healthcare coverage, accumulate state pension rights, and have protection for incapacity (sick leave), maternity/paternity, work accidents, and other contingencies.
Consequences of Not Registering
Not registering has serious repercussions. If caught operating without Social Security registration, expect fines ranging from €300 up to €3,000, plus retroactive enrollment in RETA with all missed monthly quotas and a 20% surcharge. You could also lose eligibility for the reduced "flat rate" if you don't register on time.
2. Prerequisites Before Registering
Before you attempt to register with Social Security, make sure you have completed or prepared the following prerequisites:
Essential Requirements
You need a Número de Identidad de Extranjero (NIE). For EU/EEA/Swiss citizens, a NIE and registration certificate is sufficient. Non-EU citizens must have the appropriate work authorization or self-employment visa.
You should have proof of your tax registration (such as the 'alta censal' confirmation with your CIF/NIF number and the economic activity codes) before you go to Social Security.
If you've never worked in Spain before, you may need to apply for a NUSS first. This can be done online via the Importass portal or in person at a Social Security office by submitting form TA.1.
Have your passport and NIE (Foreigner ID card) ready. For in-person registration, bring the originals and copies. For online registration, you'll use your digital ID to authenticate.
Additional Requirements
For online registration, you must have an electronic identification method setup. The Social Security online office accepts a digital certificate, Cl@ve Permanente, or Cl@ve PIN for login.
You'll need a Spanish bank account (with an IBAN in Spain) in your name, as Social Security contributions are usually paid via direct debit.
Have a working Spanish mobile number and email address. These will be used for your registration and for receiving important notifications.
Know your start date of activity, IAE code, and possibly the CNAE code. These should match the information you provided during your tax registration.
While not always required, it's wise to have a certificado de empadronamiento (town hall registration) or other proof of your address available, especially for in-person registration.
You must choose a mutua colaboradora (private mutual insurance society) to cover professional risks and manage certain benefits. Common options include FREMAP, MC Mutual, and Mutua Universal.
Timing Is Important
3. Step-by-Step Registration Process
Once you have everything ready, it's time to register with the Tesorería General de la Seguridad Social (TGSS) for the autónomo regime. There are two ways to register: online via the Social Security electronic portal, or in person at a Social Security office.
Registering Online via the Social Security Portal (Importass)
Registering online is often the fastest and most convenient method if you have a digital certificate or Cl@ve.
1Access the Importass Portal
Go to the Social Security's Importass portal for "Alta en trabajo autónomo" (self-employment registration). Navigate to the Social Security Electronic Office website and look for "Altas, Bajas y Modificaciones" → "Alta en trabajo autónomo".
2Log in with Digital Credentials
Choose your login method (digital certificate, Cl@ve PIN/Permanente, or SMS) and log in using your NIE/DNI credentials. Once logged in, the online service will start the autónomo registration application.
3Fill in Your Personal and Business Details
The online form will ask for a series of details. Provide the required information as prompted:
- Social Security Number and Personal Data
- Start Date of Activity (should match your Hacienda registration)
- Business Activity Details (IAE/CNAE codes)
- Business Address
- Estimated Income (Rendimientos Netos)
- Choose a Contribution Base
- Mutua (Insurance Fund) Selection
- Bank Account (Payment Details)
Review all the information carefully before proceeding to ensure everything is correct and matches your Hacienda registration.
4Apply the Flat Rate (if Eligible)
If you're a new autónomo (not registered as self-employed in Spain in the past 2-3 years), you likely qualify for the tarifa plana. As of 2025, the flat rate is €80 per month (about €87.60 with minor additions) for the first 12 months. Make sure to opt in during registration.
5Submit the Application
Once everything is filled in and double-checked, submit the online form. In many cases, you'll get an immediate confirmation screen acknowledging your alta in RETA, often with a downloadable PDF confirmation. Save this for your records.
6Note the Seguridad Social Account Credentials
Your Social Security number (NAF) will be your reference for all future inquiries. You can continue to use the Importass portal to manage your account and access services like "Tu Seguridad Social."
Registering In Person at a Social Security Office
If you prefer a face-to-face process or don't have the digital means to do it online, you can register by visiting your local Social Security Treasury office.
1Find and Make an Appointment (Cita Previa)
Find your local TGSS office using the official TGSS website or through a search like "Oficina TGSS + [your city]". Many offices require an appointment for autónomo registration, which can be requested online at sede.seg-social.gob.es (look for "Cita Previa") or by phone.
2Download and Complete Form TA.0521
Prior to visiting, you should download and fill out Form TA.0521 (Application for Registration in RETA), which can be found on the Social Security website under "Forms" or "Formularios". Complete as much of it as you can before your appointment.
3Gather Your Documents
On the day of your appointment, bring:
- Completed Form TA.0521
- Your NIE and original passport (plus photocopies)
- Proof of your tax registration at Hacienda (alta censal/Modelo 036/037 confirmation)
- Bank details for direct debit payment of your monthly fees
- Spanish address proof (if available, like an empadronamiento or utility bill)
4Submit Your Application in Person
At the office, inform the staff you want to register as an autónomo (alta en RETA). The official will check your documentation, ask questions to clarify any details, and process your application. They will also explain the contribution rates and ask you to select a mutual insurance society if you haven't already decided.
5Request the Flat Rate (if Eligible)
If you qualify for the tarifa plana (reduced rate for new autónomos), make sure to inform the official and request it explicitly during your appointment. They should check your eligibility and apply it to your registration.
6Receive Confirmation
If all goes well, you should receive immediate confirmation of your registration and your Social Security affiliation number if you don't already have one. Request a printed copy of your alta confirmation for your records.
4. After Registration – What to Expect
Once you've successfully registered with Social Security as an autónomo, here's what happens next:
Monthly Contributions
The Social Security Treasury will automatically debit your Spanish bank account around the end of each month for your autónomo contribution. The amount depends on your chosen base rate or the flat rate if you qualify. For new autónomos in 2025, the first year starts at approximately €80 per month with the flat rate.
Healthcare Coverage Activation
Your registration automatically entitles you to Spain's public healthcare system. Within a few days of registration, you should visit your local health center with your Social Security document to register with a doctor and get your health card (tarjeta sanitaria).
Digital Access to Your Account
You can now access the "Tu Seguridad Social" and "Importass" sections on the Social Security website to check your status, download proof of payments, and handle future modifications to your registration.
Tax Impact and Deductions
Your Social Security contributions will be tax-deductible in your quarterly and annual tax returns. Keep all receipts and confirmations for your tax records, as they represent a significant expense that reduces your taxable income.
Important Notice About Contribution Rates
5. Common Mistakes to Avoid
Here are common pitfalls to be aware of when registering for Social Security as an autónomo, and how to avoid them:
Late Registration
Issue: Delaying your Social Security registration beyond your start date can lead to fines, back payments with surcharges, and loss of flat rate eligibility.
Solution: Register at the same time as your tax registration or no later than the day you start your business activity. If there's a legitimate reason for a delay, consult with an advisor about potential remedies.
Mismatched Information
Issue: Providing different information (like start dates, activity codes, or addresses) between your Hacienda and Social Security registrations can trigger red flags and complicate your taxes.
Solution: Ensure all details match exactly what you provided during your tax registration. Keep copies of both registrations for reference and consistency.
Missing the Flat Rate Application
Issue: Forgetting to specifically request the tarifa plana if you're eligible, as it's not always automatically applied even if you qualify.
Solution: During your registration, explicitly state that you're a new autónomo and want to apply for the flat rate. If registering online, look for the corresponding checkbox or option. If in person, verbally confirm this with the official.
Incorrect Contribution Base Selection
Issue: Choosing an inappropriately high contribution base that leads to excessive monthly payments, or a very low base that results in reduced benefits.
Solution: Under the new progressive system, select a contribution base that realistically aligns with your expected earnings. If unsure, start with the appropriate bracket for your expected income level and adjust later if necessary.
Forgetting to Monitor Your Account
Issue: Not checking your Social Security account regularly, missing important notifications or payment issues.
Solution: Set a monthly reminder to log into your Importass account to verify that payments are being processed correctly and to check for any communications or changes to your status.
6. Your Next Steps After RETA Registration
After successfully registering with both Hacienda and Social Security, you're now officially an autónomo in Spain. Here's what comes next in your journey:
What's Next in Your Autónomo Journey
Learn how to create proper invoices that include all required information, IVA (if applicable), and IRPF withholding. See our separate invoicing guide for detailed instructions.
Mark your calendar for quarterly IVA and IRPF filing deadlines (typically January 20, April 20, July 20, and October 20). Start tracking your income and expenses from day one.
Visit your local health center to register and obtain your public healthcare card. Bring your Social Security documentation and proof of identity.
Depending on your profession, you might want to obtain professional liability insurance (seguro de responsabilidad civil) to protect yourself from potential claims.
With both registrations complete, you now have the legal foundation to operate your freelance business in Spain. Remember to stay on top of your tax obligations and keep detailed records of all business transactions and expenses.
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