2026 tax deadlines for self-employed workers in Portugal

Social Security

• Quarterly declaration: by 2 February (31 January was a Saturday), 30 April, 31 July and 2 November (31 October was a Saturday). How much you pay: Social Security guide.
• Payment: every month, between the 10th and the 20th, of the previous month’s contribution. See how much you will pay.
• Late declaration: online, until the last day of the month before the next period. The October declaration can still be submitted in November and December (Segurança Social Practical Guide).

IRS

• By 2 March: mark in e-Fatura which expenses belong to your activity and confirm your household (agregado familiar) (the legal deadline is the end of February). See how to validate invoices in e-Fatura.
• 16 to 31 March: check your deductible expenses and, if there are mistakes, complain about general household expenses and the expenses for requesting invoices (the AT publishes the amounts by 15 March).
• 1 April to 30 June: file the IRS return (Modelo 3 with Anexo B). See how to file IRS on recibos verdes. If you are 35 or younger, do not forget to opt for IRS Jovem.
• By 31 August: refund or payment, for returns filed on time (AT leaflet «Principais prazos» (main deadlines)).
• Payments on account (only if the Finanças ask you): by 20 July, 21 September and 21 December (AT Tax Calendar 2026 (Agenda Fiscal)).

Payments on account (pagamentos por conta) are advance payments of the current year’s IRS. They are worked out from the IRS of two years earlier, minus that year’s withholding. A payment below €50 is not required, and you can stop paying if the withholding and payments already made are enough to cover the year’s tax (CIRS, article 102).

VAT (normal quarterly regime)

Only if you are not exempt under article 53. Not sure whether you are exempt? Use the VAT exemption checker. To fill in the return, read the guide to the periodic VAT return.

The return is due by the 20th of the 2nd month after the quarter, and the 2nd quarter has a deadline of 20 September, which in 2026 was a Sunday (CIVA, article 41). Payment is due by the 25th of the same months (AT Tax Calendar 2026 (Agenda Fiscal)).

When the deadline falls on a weekend

If the last day of a deadline is a Saturday, Sunday or public holiday, the deadline moves to the next working day (AT newsletter of January 2026). This is what happened in 2026:

• 28 February was a Saturday: the e-Fatura deadline moved to 2 March.
• 20 September was a Sunday: the 2nd-quarter VAT return and the 2nd payment on account moved to 21 September.
• 20 December is a Sunday: the 3rd payment on account moves to 21 December.

What is still left in 2026

First 2027 deadlines (expected)

These dates are expected, worked out from the current rules and the next-working-day rule. Check them in the AT’s 2027 Tax Calendar when it is published.

• 20 January: pay the December 2026 contribution (from 10 to 20 January).
• 1 February: quarterly declaration for October to December and confirmation of the 2026 amounts (31 January 2027 is a Sunday).
• 22 February and 25 February: VAT return and payment for the 4th quarter of 2026.
• 1 March: e-Fatura and household details (28 February 2027 is a Sunday).
• 1 April to 30 June 2027: file IRS for your 2026 income.

Example: your first year of activity

You open activity in March 2026, exempt from VAT, and issue receipts to companies. What applies to you until mid-2027:

1. VAT: while you are exempt, you have no periodic returns.
2. Social Security: the obligation to contribute starts on 1 March 2027, the 1st day of the 12th month. The first contribution is paid between 10 and 20 April 2027.
3. IRS: you declare your 2026 income between 1 April and 30 June 2027.
4. Payments on account: they use the IRS of two years earlier, so the first ones you may be asked for are those of 2028.

Common mistakes

• Confusing declaring with paying: for Social Security you declare every 3 months, but you pay every month.
• Looking for the 2nd-quarter VAT deadline in August: it is in September.
• Making a payment on account you were not asked for: you only pay if the Finanças send you the amount.
• Forgetting e-Fatura: the deadline to mark business expenses ends at the end of February, a month before IRS filing starts.

Open the calendar and add the deadlines to your phone

Frequently asked questions

When is IRS on 2026 income filed?

Between 1 April and 30 June 2027.

By what day is Social Security paid?

By the 20th of each month (payment between the 10th and the 20th), for the previous month.

If the deadline falls on a Saturday, what happens?

It moves to the next working day, as the AT explains in its January 2026 newsletter.

When is the deadline for 2nd-quarter VAT?

By 20 September. In 2026, as it was a Sunday, it moved to 21 September 2026; payment is due by the 25th.

Do I have to make payments on account?

Only if the Finanças ask you to. The amount appears on the IRS assessment notice (nota de liquidação) and a payment below €50 is not required.

I forgot the October quarterly declaration. Am I still in time?

Yes. Online, you can submit it late in November and December.

Official sources

Every figure on this page comes from these sources (official documents, in Portuguese). Updated on 11 November 2026

• Portal das Finanças — IRS: principais prazos em 2026 (opens in a new window)
• Portal das Finanças — Agenda Fiscal 2026 (obrigações de pagamento) (opens in a new window)
• CIVA, art.º 41.º — Prazo da declaração periódica (inclui n.º 10: 2.º trimestre até 20 de setembro) (opens in a new window)
• Segurança Social — Guia Prático "Novo Regime dos Trabalhadores Independentes" (v1.09, 12/01/2026) (opens in a new window)
• AT — Newsletter n.º 39, janeiro de 2026 (prazos em dia não útil) (opens in a new window)
• CIRS, art.º 102.º — Pagamentos por conta (Portal das Finanças) (opens in a new window)