First-year runway for a freelancer with irregular income

Terms used

• Autónomo — An autónomo is a self-employed worker registered to work on their own account in Spain.
• RETA — RETA is the social security scheme for self-employed workers.
• Cuota — The cuota is the monthly social security contribution an autónomo pays.
• Tarifa plana — The tarifa plana is the reduced flat-rate cuota for new autónomos, 80 euros a month in the first 12 months.
• IVA — IVA is Spain's value added tax (VAT), charged on most goods and services.
• IRPF — IRPF is Spain's personal income tax.
• Modelo 303 — Modelo 303 is the quarterly VAT return.
• Modelo 130 — Modelo 130 is the quarterly advance payment of income tax for self-employed workers.

Key rules

• Monthly cuota: You owe the social security contribution every month, even in a month with no income.
• Tarifa plana: The flat rate is not permanent, so budget for the higher standard cuota from the start.
• VAT money: The VAT you charge clients is not your income, so set it aside when you are paid.
• Modelo 130: You may not need the income tax advance if at least 70 percent of your invoices have withholding tax.
• Last quarter: The final quarterly returns are due by 30 January.

The bottom line

Your autónomo costs do not depend on whether you got paid. The monthly social security payment is due every month, and the tax returns are due every quarter. Your runway is the cash that covers these bills through your slowest months.

This page covers the cash planning. How to register and how contributions work in detail belong to the self-employment pages.

Fixed monthly cost: your social security contribution

You pay a monthly contribution (cuota) to the autónomo system (RETA). It is based on your real net income, across 15 income brackets. In 2025 the lowest bracket cost about 200 euros a month and the highest about 590 euros. The standard cuota is around 31 percent of the base you choose. The brackets are updated every year, so check the current table.

New autónomos can use the tarifa plana, a flat rate of 80 euros a month for the first 12 months. It can be extended for another 12 months if your net income stays below the minimum wage. You do not qualify if you were an autónomo in the last 2 years, or 3 years if you used the flat rate before.

Plan for the day the flat rate ends. Your cuota then moves to the standard amount, so budget the higher figure before it arrives.

Fixed quarterly costs: tax returns

Most freelancers file two returns each quarter:

• Modelo 303 is the VAT (IVA) return. You pay the VAT you charged clients, minus the VAT you paid on business costs.
• Modelo 130 is an advance payment of income tax (IRPF), set at 20 percent of your net profit.

The deadlines are 1–20 April, July and October. The last quarter is due by 30 January. The timeline below shows the full calendar.

Some of you will not need all of these:

• You skip modelo 130 if at least 70 percent of your invoices have withholding tax applied, which is common for professionals.
• You skip modelo 303 if your activity is exempt from VAT, such as some health and education services.
• Activities under the module regime have their own rules (modelo 131).
• Work for EU clients may also need modelo 349.

After the year ends, you also file the annual income tax return (Renta) in spring and the VAT summary, modelo 390. Basque Country and Navarre have their own regimes, so check locally if you live there.

Build the runway

1. Add up the monthly fixed costs. Use the flat rate while it lasts, and also work out the standard cuota.
2. Set aside tax money from every payment. The VAT you charge is not yours. Put it in a separate account as soon as a client pays. Do the same for the 20 percent income tax advance if it applies to you.
3. Keep a buffer of several months of fixed costs. Aim to cover your cuota, your quarterly tax and your living costs through a gap in income. A longer buffer is safer if your clients pay late.
4. Plan for the January payment. The last quarter is due on 30 January, right after the slow holiday period for many freelancers.

A month with no income still costs you the cuota. A quarter with income but no cash set aside can leave you short for tax. Keeping tax money apart protects you against the second problem.

Check the figures

Contribution brackets and amounts change every year. Check the current table with the Seguridad Social, and ask a gestor (an accountant who handles filings) which returns apply to your activity.

Timeline and deadlines

• Pay your monthly social security contribution: Every month, whatever you earned; 80 euros on the flat rate for the first 12 months

• File the VAT return (modelo 303) and, if it applies, the income tax advance payment (modelo 130): 1 to 20 April for the first quarter

• File the second quarter returns: 1 to 20 July

• File the third quarter returns: 1 to 20 October

• File the last quarter returns: 1 to 30 January

• Move to the standard contribution if the flat rate ends: After month 12, unless your net income stays below the minimum wage and you get the 12-month extension

Frequently asked questions

Does the flat rate last for the whole first year?

Yes, the flat rate of 80 euros per month applies for the first 12 months for new autónomos. It can be extended by another 12 months if your net income stays below the minimum wage. It does not apply if you were an autónomo in the previous 2 years, or 3 if you used the flat rate before.

Do I always have to file the income tax advance payment every quarter?

No, you can skip the quarterly income tax advance payment (modelo 130) if at least 70 percent of your invoices already have withholding tax applied. This usually fits professionals who invoice companies. Activities under the module regime follow their own rules instead.

Which quarterly tax deadline falls latest in the year?

The last quarter's returns are due by 30 January, later than the 20th of April, July and October. The VAT return for that quarter is due on the same date. Plan cash for it in the quiet weeks after year end.