When do I need to file my tax return if I'm self-employed?

What country are you in? Because the deadlines vary quite a bit depending on where you file.

If it's in Latin America, generally the period to file is in the first quarter of the following year (January-March roughly), but this changes depending on the country and your tax regime. In some places like Colombia or Mexico the deadlines are different, and in others like Argentina it depends on your taxpayer number. If you're late there are fines, which are usually a percentage of what you owed, so it's worth not leaving it till the last minute. Best thing is to check directly with your country's tax authority or with an accountant, because each jurisdiction has its own rules and exceptions depending on the type of activity you do.

I'm guessing you're talking about Spain, right? If so, you have from January 1st through June 30th of the following year to file your return, so for example for 2025 you'd have until the end of June 2026. If you miss the deadline without a valid reason, the tax authorities will hit you with surcharges ranging from 5% to 20% depending on how late you are, so it's not something to mess around with.

What most people don't mention is that if you file through a tax advisor or accountant, they usually have to submit it by the end of April, so technically you'd have a shorter deadline but without having to worry about anything. It's a pretty handy workaround if you're the type who always leaves it until the last minute!

The deadlines really depend on where you're running your business, because the dates change a lot from one country to another. I'm guessing you're asking about Spain since the other comments are heading that way, but if it's another Latin American country let me know and I'll give you different info.

In Spain, as a self-employed person, you have until June 30th of the following year to file your income tax return for the previous fiscal year. So for 2025, for example, you'd file between January and June of 2026. The filing deadline also includes your quarterly VAT declaration (you get a month each quarter to submit it), which is mandatory if you exceeded certain billing thresholds. Penalties exist and they're not friendly at all: if you're late, the Tax Agency charges you late-payment interest plus a fine that can range from 5% to 150% of the amount owed, depending on how late you are and whether it was negligence or fraud.

The best thing is to keep everything organized from now on. There are accounting firms that help with this (some are pretty affordable for small businesses) or you can use online platforms that make the process easier. The important thing is not to leave this for last minute: I've seen people wait until June and when they realize their documentation is incomplete it's already too late to fix it without a fine.