Here is exactly how to register as autónomo with Social Security in Spain using Importass. You will see the steps, what data you must have ready, timing rules, what to choose for your base, and how the €80 flat rate works. Since 2018, autónomos must do these trámites online, so you will need Cl@ve or a digital certificate. If you were searching “how to register as autonomy with social security,” this is the same process, just using the correct Spanish terms.
Q&A
Do I register first with AEAT or Social Security?
Register with the Tax Agency (AEAT) and Social Security the same day is fine. Practically, get your AEAT alta first so you already know your IAE code.
Can I file the alta in advance?
Yes. You can file your Social Security alta up to 60 days before your start date.
What login do I need?
Cl@ve or a digital certificate. Both work in Importass.
What if I start working before filing?
You can still file, but it is “out of term” and can mean surcharges or back payments.
When is the Social Security payment charged?
On the last business day of each month by direct debit.
Is the €80 flat rate for everyone?
It applies to new autónomos who meet eligibility rules. If your income stays under SMI, you can extend it for 12 more months.
How to register as autónomo with Social Security
- Prerequisite: have your AEAT alta and IAE epígrafe.
- Go to Importass → “Alta en trabajo autónomo”.
- Identify yourself with Cl@ve or digital certificate.
- Fill the form: IAE and CNAE, start date, address, estimated monthly net income, contribution base, mutua, and bank account.
- Submit on or before day one. Download the receipt and keep it.
- Check here our YouTube video-tutorial for free.
Step by step: RETA registration in Importass
1. Access Importass
Go to the platform and choose “Altas, bajas y modificaciones”, then select “Alta en trabajo autónomo.”
2. Identify yourself
Use your Cl@ve credentials or a digital certificate.
3. Have this ready
• IAE epígrafe from your AEAT registration
• CNAE code
• Start date and business address
• Estimate of your average monthly net income for the year
• Choice of mutua (the insurer that manages benefits like sick leave)
• IBAN for direct debit
4. Complete the form sections
(see below)
- Last step: enter your IBAN for direct debit and review all your information.
Submit and save proof. You will get a confirmation. Later, your “vida laboral” will show the alta.
Deadlines and timing to avoid surcharges
- Before you start. You must be in RETA on or before your first day of activity.
- 60-day advance window. You can file early to avoid last-minute issues.
- Late filing. Allowed, but considered out of term and may trigger recargos.
- Coordinate with AEAT. Many people pre-file both the AEAT alta and the Social Security alta the same day.
Choosing your contribution base under the 2025 real-income bands
Spain now uses real-income bands. You estimate your average monthly net income and choose a base inside the corresponding band. Your monthly cuota depends on that base.
- There are multiple bands from low to high income.
- You can change your base up to six times per year to track your income.
- A small MEI surcharge applies to all workers for system sustainability.
- Higher base means higher protection for sick leave, maternity or paternity, and future pension.
Simple rule of thumb: pick a base that fits your income, then adjust during the year if your income changes.
Flat rate €80 and pluriactividad
Tarifa plana €80.
- New autónomos pay €80 per month for the first 12 months.
- If your net income stays below SMI, you can get 12 extra months at €80.
- You must not have recent prior use that blocks eligibility, and you cannot have debts with AEAT or TGSS.
Pluriactividad.
If you are also an employee, you are in pluriactividad. Your reductions differ from tarifa plana. Sometimes pluriactividad gives a better result than €80. Pick based on your case. If unsure, compare both or ask an expert.
Mutua and coverages you must choose
Mutua is the collaborating insurer that handles your benefits. You must select one during alta.
- Common contingencies. Always included.
- Accidents at work and occupational disease. Required for some activities, advisable for higher-risk jobs.
- Cese de actividad. Protection similar to unemployment for autónomos if conditions are met.
Pick a mutua with good digital claims handling. You can request changes later if needed.
Paying your Social Security: when and how it is charged
- Charge date. The cuota is charged by direct debit on the last business day of each month. It is paid in arrears, so your first charge arrives after your first month.
- Visibility. From around the 26th each month, you can view the charge amount in your online area.
- Bank changes. If you change IBAN mid-month, it may apply the next month. Do it early to be safe.
- Missed payment. Keep enough balance on charge date. If a charge fails, pay quickly to avoid recargos.
After your alta: what to check next
- Download the alta proof and keep it with your AEAT alta.
- Check your vida laboral later to confirm your registration dates.
- Review your base and cuota regularly. If your income changes, request a base change. You can do this up to six times per year.
- Watch your electronic notifications. TGSS can send regularization notices if your final IRPF net income and chosen base do not match.
Common mistakes that delay or invalidate your alta
- Filing after you started to work. File on or before day one.
- Choosing a CNAE or IAE that does not match what you actually do.
- Forgetting to select a mutua. The form will block you, but double-check.
- Estimating income unrealistically, then being surprised by regularization.
- Missing the month-end charge because of low balance.
Pro tip if you want less admin: renn can pre-check your IAE and CNAE, estimate your quota, watch your income vs base through the year, and nudge you to adjust so you avoid surprises. It also keeps all documents in one place and syncs your invoices with your taxes.
Bottom line
To register as autónomo with Social Security successfully, use Importass, file on or before your start date, and have these ready: IAE and CNAE, start date, income estimate, mutua choice, and IBAN. Pick a contribution base that matches your income, use the €80 flat rate if you qualify, and review your charges each month.
