How to Register as a Sole Proprietor (Autónomo/a) in Spain: A Complete 2025 Guide

Setting up as an autónomo/a, Spain’s equivalent of a self-employed sole proprietor, remains one of the quickest ways to start working independently. Once registered, you can invoice clients, deduct eligible business expenses, and operate with full professional autonomy. For most freelancers, consultants and digital workers, nearly the entire process can be completed online through the Spanish Tax Agency (Agencia Tributaria) and Social Security (TGSS).

If you already have a Spanish digital identity (Cl@ve or an FNMT digital certificate), registration is usually completed the same day. While the steps are relatively straightforward, expect formal paperwork, clear deadlines, and recurring declarations such as VAT filings (if applicable), quarterly income-tax prepayments, and monthly Social Security contributions aligned with your net earnings.

This guide breaks down everything you need to know to start and maintain your activity legally in Spain.

Disclaimer: This content is for informational purposes only and does not replace legal or fiscal advice. Always consult official sources or a qualified advisor before taking action.

What is a Sole Proprietorship in Spain?

A Spanish sole proprietorship is known as a trabajador autónomo / persona trabajadora por cuenta propia. You operate as an individual rather than forming a company, which means quick setup, minimal bureaucracy, and no minimum capital. To become an autónomo, you must:

• Register for tax purposes with the Agencia Tributaria, and

• Join the RETA (the Social Security scheme for self-employed workers).

Key Facts About the Autonomous Worker Structure

Official name: Trabajador autónomo / persona trabajadora por cuenta propia
Registration bodies:

• Agencia Tributaria – Tax census via Modelo 036 or 037

• Tesorería General de la Seguridad Social (TGSS) – RETA registration via Importass
  Minimum capital required: None
  Liability: Unlimited personal liability (business and personal assets are legally connected). Professional liability insurance is strongly recommended for risk-exposed professions.
  Tax treatment:

• Income is taxed through personal IRPF.

• Quarterly prepayments may be required depending on your accounting method.

• VAT (IVA) applies to most activities unless exempt.
  Naming rules: Operate under your legal name or add a trade name (optional). Trade names and trademarks can be registered with the OEPM.
  Main advantages: Very fast setup, low initial cost, and simple deregistration.
  Main disadvantages: Unlimited liability and mandatory monthly Social Security payments, even during slow months (with limited exceptions).

Autónomo vs. Spanish Limited Company (SL): What’s the Difference?

While both structures let you conduct business legally, they differ in cost, liability, complexity, and tax treatment.

Step-by-Step: How to Register as a Sole Proprietor (Autónomo/a) in Spain

Step 1: Confirm You Are Eligible

To work as an autónomo, you must have a valid Spanish tax identification number:

• Spanish nationals: DNI

• Foreign nationals: NIE

EU/EEA/Swiss citizens staying over three months must register using form EX-18.
Non-EU citizens typically need a self-employment residence and work authorization (form EX-07).

Step 2: Set Up Your Digital Identity

Because Spanish bureaucracy is now largely digital, you should obtain:

• Cl@ve credentials, or

• An FNMT digital certificate

Both are free and accepted by all public administrations.

Step 3: Choose How Your Business Will Be Identified

You may operate:

• Under your full legal name, or

• With an optional trade name (nombre comercial)

Trade names and trademarks can be secured via the OEPM’s registry and checked in their availability search tool.

Step 4: Register with the Spanish Tax Agency (AEAT)

Before you begin billing clients, you must file the census declaration (alta censal) using:

• Modelo 036 (standard form), or

• Modelo 037 (simplified version)

You will choose your IAE activity category, declare whether you are subject to VAT, and, if you will operate cross-border, request your intra-EU VAT operator number (ROI/VIES).

Step 5: Join the Spanish Social Security System (RETA)

Next, enroll in the Regimen Especial de Trabajadores Autónomos (RETA) through TGSS’s Importass portal.

You will:

• Estimate your monthly net income

• Select a contribution base within the official brackets

• Apply for available reductions (including the €80/month reduced rate for eligible new autónomos)

Step 6: Start Invoicing and Stay Compliant

Once registered with AEAT and TGSS, you may legally invoice. Spain requires invoices to include specific data such as tax ID, invoice number, description of service and VAT rate (if applicable).

You are also required to follow Spain’s certified e-invoicing and Verifactu* regulations as they roll out, so ensure your invoicing software meets AEAT requirements.

Financial and Tax Responsibilities for Autónomos in Spain

Income Tax (IRPF)

Self-employed workers pay IRPF on their annual profits. Many freelancers also file quarterly payments (Modelo 130), depending on their accounting method.

Social Security Contributions

Since 2023, autónomo contributions are income-based. Each bracket has a corresponding monthly rate. You can adjust your income forecast several times per year.

The general contribution rate for 2025 is 31.40% applied to your selected base.
A reduced €80/month flat rate is available to qualifying new autónomos for the first 12 months.

VAT (IVA)

Most services are subject to the general 21% VAT rate,with reduced rates applied in certain cases. VAT is reported quarterly via Modelo 303, plus annual summaries where relevant.

Mandatory Record-Keeping

Keep organized books of:

• Income and expenses

• Issued and received invoices

• VAT ledger (if applicable)

Electronic bookkeeping is fully accepted by AEAT.

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