Can I invoice without being autónomo?

To issue an invoice and declare the income you normally need at least the tax registration (modelo 036). Whether you must also pay into the RETA depends on whether the activity is habitual. Income is always declared.

What is the limit for invoicing as an individual?

There is no legal threshold that exempts you from registering. Case law uses the annual minimum wage as an indicator of non-habituality for the RETA, but it is not a rule and Social Security can still claim. Any amount is declared to the Tax Agency.

What happens if the Tax Agency or Social Security find out?

You could face Tax Agency penalties for not declaring and claims for back RETA contributions with surcharges. It is better to classify the case correctly from the start.

Being autónomo

Can I freelance in Spain without being autónomo?

Updated on July 7, 2026

The answer has nuances. To issue an invoice and declare the income, in practice you need at least the tax registration (modelo 036), and that income goes into your Spanish income tax whatever the amount. Paying into the RETA (Social Security) depends on whether the activity is "habitual". There is no legal threshold that exempts you from registering — only a judicial criterion that uses the minimum wage as an indicator.

Two obligations that are not the same

There are two separate things here. For the Tax Agency, to issue an invoice and declare the income you normally need to register (modelo 036) and include that income in your Spanish income tax, whatever the amount. For Social Security, the duty to contribute to the RETA scheme depends on whether the activity is "habitual". You may need to be registered with the Tax Agency but not necessarily with the RETA for a one-off job.

There is no "magic threshold" that lets you invoice without being autónomo. All income must be declared; what is debatable is whether the activity also requires paying into the RETA.

One-off work vs. habitual activity

The key for Social Security is "habituality". An isolated, occasional job is easier to defend as non-habitual than a recurring activity. Spanish case law has used the annual minimum wage (SMI) as an indicator: below it, it is more arguable that the activity is not habitual. But this is a judicial criterion, not a legal exemption — the Social Security Treasury can still claim the registration and the back contributions.

How to declare one-off income

1Register with the Tax Agency (modelo 036) so you can issue the invoice correctly.
2Issue the invoice with the applicable VAT and apply income-tax withholding if the client is a company or self-employed.
3Include the income in your annual tax return.
4If the activity is not habitual, assess carefully (ideally with advice) whether RETA registration applies.

The risks of getting it wrong

Getting paid without declaring can lead to Tax Agency penalties and claims for back Social Security contributions with surcharges. Do not treat "invoicing without being autónomo" as a shortcut: treat it as a case that needs to be classified correctly.

Frequently asked questions

Official sources

This guide is general information and does not constitute personalised tax advice. Always check the official sources or a professional before deciding.