Self-employed Social Security in Portugal: how much you pay

How the self-employed pay Social Security

Unlike an employee, a self-employed worker does not have the contribution deducted automatically each month by an employer. They report what they received and pay their Social Security contribution from that figure. The mechanism has three parts: the quarterly declaration, the relevant income and the contribution base.

The quarterly declaration

Four times a year, in January, April, July and October, the self-employed worker reports to Social Security what they received over the previous three months¹. This declaration sets the base they will contribute on in the following quarter.

The declaration is filed even when there was no income in the quarter. In that case the base is zero, but, as we will see, there is still a minimum amount to pay.

From relevant income to the contribution base

The rate does not apply to everything you bill. First the relevant income is worked out, which depends on the type of activity¹:

The monthly contribution base is then 1/3 of the quarter's relevant income, the monthly average of the three months reported².

Monthly base = (70% of services + 20% of goods) for the quarter ÷ 3

The rate: 21.4% (or 25.2%)

The contribution rate is applied to the base¹:

• 21.4% for the self-employed worker (the general case);
• 25.2% for the sole trader (ENI, the holder of an individual limited liability establishment and their spouse).

The monthly contribution is therefore the base × rate.

The minimum and the ceiling

There are two important limits:

• Minimum: €20/month. The monthly contribution is never less than €20. Even with no income, or very low income, an enrolled worker pays at least €20 a month¹.
• Maximum: a base of 12 × IAS. The contribution base cannot exceed 12 times the IAS per month. In 2026, with the IAS at €537.13³, that is a €6,445.56 maximum base, which caps the contribution for higher incomes.

Worked example

Say you invoiced €7,500 of services in a quarter (about €2,500/month):

• Relevant income: 70% of €7,500 = €5,250.
• Monthly contribution base: €5,250 ÷ 3 = €1,750.
• Monthly contribution: 21.4% of €1,750 = €374.50.
• For the quarter: €374.50 × 3 = €1,123.50.

Run the numbers with your own figures in the self-employed Social Security calculator.

The voluntary ±25% adjustment

In the quarterly declaration, you can adjust the assessed base up or down, by up to 25%, in 5-point steps¹. Anyone expecting the next quarter to be very different from the last uses this adjustment to bring the contribution closer to reality, for example lowering the base when activity slows, or raising it to strengthen their contributory record.

The first-year exemption

If you are starting an activity for the first time, you are generally exempt from the contribution for the first 12 months¹. The first mandatory contribution arises in the 12th month after activity starts. It is an important relief at the start of working for yourself.

There is also an exemption when combining jobs: someone who simultaneously has employed work paying at least 1 IAS a month and an average relevant income as a self-employed worker that does not exceed 4 × IAS may be exempt from contributing as self-employed. It is a specific case the calculator does not handle, but worth confirming on Segurança Social Direta.

Social Security is not IRS

Finally, a distinction that confuses many people: Social Security (this calculation) and Category B IRS are two different charges, each with its own rules. This calculator estimates Social Security only. To see both together, with simplified-regime IRS and your net income, use the recibos verdes calculator.