How to Register as an Autonomo in Spain: Complete 2026 Guide

Registering as an autonomo in Spain is simpler than it looks. Here are the concrete steps to do it right from the start.

Step 1: Register with the Tax Authority (Modelo 036/037)

Before you start invoicing, you must file Modelo 036 or 037 with the AEAT (Agencia Tributaria). Choose the IAE code that best describes your activity. Modelo 037 is the simplified version, most used by freelancers without special activities.

Step 2: Register with Social Security (RETA)

Within 30 calendar days of registering with the tax authority, you must join the RETA (Regimen Especial de Trabajadores Autonomos). Since 2023, contributions are calculated based on your actual net income. If you're just starting and expect low income, you'll pay less.

Autonomo fees in 2026

The minimum fee depends on your income bracket. For income below EUR 670/month, the fee is approximately EUR 200/month. Higher earnings mean higher contributions.

New freelancer discount

If this is your first time registering, you may qualify for the flat rate (tarifa plana). In 2026, this is EUR 80/month for the first 12 months if income is below the minimum wage.

Step 3: Set up your invoicing software

Once registered, you need a legal invoicing system. From July 2027, all invoices must comply with Verifactu. Don't wait — k-factu is compliant from day one and costs EUR 9.99/month.