Form 130 Explained: Who Files It and How Self-Employed Quarterly Income Tax Payments Are Calculated

If you are self-employed and taxed under the direct estimation method, every quarter you face a filing that raises plenty of questions: Form 130 (modelo 130). It is not a new tax, but an advance payment of your annual income tax (IRPF). The better you understand it, the fewer surprises you will get when your annual income tax return comes around.

What Form 130 is and who has to file it

Form 130 is the self-assessment of the IRPF instalment payment for business owners and professionals whose income is determined under the direct estimation method, whether normal or simplified. It works as an advance: what you pay during the year is later deducted from the tax due on your annual return.

As a general rule, it is mandatory for self-employed individuals carrying on economic activities under direct estimation. Those taxed under the objective estimation method (modules) do not use this form, but Form 131.

There is one important exception: you are exempt from filing if, in the previous year, at least 70% of your business income was subject to withholding or payment on account. This is the typical case of professionals who invoice almost entirely to companies and issue their invoices with withholding. In 2026, therefore, you need to look at your 2025 income.

If you are exempt, you do not file the form. If you do not meet the requirement, you must file it every quarter, even when the result is zero or negative. Anyone starting an activity has no previous year to compare with, so they will usually have to file from the outset.

How the 20% is calculated

The key point is that the calculation is cumulative from 1 January, not quarter by quarter in isolation. The general mechanics are:

1. Add up all taxable income for the year up to the end of the quarter.
2. Subtract tax-deductible expenses, also cumulative. Under the simplified method, the deduction for hard-to-document expenses also applies, subject to its cap.
3. Apply 20% to the resulting net income.
4. Subtract the instalments already paid in previous quarters and the withholdings your clients have applied during the period.

An example with round numbers. In the first quarter you invoice €10,000 and have €4,000 of deductible expenses: net income of €6,000, and 20% is €1,200 to pay. In the second quarter, the year-to-date total is €22,000 of income and €9,000 of expenses: net income of €13,000, and 20% is €2,600. Since you already paid €1,200, you now pay €1,400 (less any withholdings you have borne).

If the result for a quarter is negative, you pay nothing, but the form must still be filed. In addition, there are further deductions for low net income, which you should check on the form itself depending on your situation.

As for deadlines, the form is filed during the first twenty calendar days of April, July and October, and the fourth-quarter form by 30 January. It is 10 October: the third-quarter 2026 form is due on the 20th of this month.

Common mistakes to avoid

Calculating only the quarter. This is the most frequent mistake. Because the calculation is cumulative, if you forget to deduct previous payments you overpay; if you omit income from earlier quarters, you underpay and risk a tax authority notice.

Not deducting withholdings. If your invoices carry withholding, that amount has already been paid in your name and must be subtracted. Forgetting it means advancing money to the tax authority unnecessarily.

Filing when you are exempt, or the other way round. Check every year the percentage of income with withholding for the previous year. A change in your client base can move you from one regime to the other.

Deducting expenses without a valid receipt. Only expenses related to the activity, properly documented and correctly recorded count. An expense without an invoice is a risk in an inspection.

Missing the deadline because the result is negative. A zero return must also be filed. If you do not, you may face avoidable surcharges or penalties.

Confusing it with VAT. Form 130 is for IRPF and Form 303 is for VAT. Even if the dates coincide, they are different calculations and are filed separately.

At Zythos Business we keep the books of self-employed professionals and small businesses with orderly quarterly closings, so Form 130 comes from reconciled data and not from a rough estimate. We check whether you need to file it, make sure expenses and withholdings are properly recorded, and warn you well in advance of every deadline, so that the IRPF advance becomes routine rather than a shock.