Social Security for Freelancers in Portugal: The October Payment and the Q3 Declaration
By Mikael
October has two Social Security dates for a trabalhador independente on recibos verdes.
The first is the payment of September's contribution, between the 10th and the 20th. The second is the Declaração Trimestral for July, August and September, due on 31 October.
This post covers what each one is, how the contribution is worked out, what happens if you are late, and the rules that change things in your first year.
10 to 20 October: pay September's contribution
Contributions are monthly. A month's contribution is paid between the 10th and the 20th of the month after it, so September's falls in this window.
The declaration is quarterly and the payments are monthly. Four declarations a year do not mean four payments a year.
Segurança Social offers direct debit. Its own guide prints the route as "Conta Corrente" » "Posição atual" » "Pagamentos à Segurança Social" » "Autorizar Débito Direto para Pagamento de Contribuições".
Direct debit only collects the current month's contribution. If you owe an earlier month or interest, you pay that separately.
To see the contributions Segurança Social has calculated for you, its guide points to "Emprego" » "Consultar Contribuições".
31 October: file the Q3 Declaração Trimestral
The Declaração Trimestral is your declaration of the income you obtained in the three previous months. For this one, that means July, August and September.
The deadline for each quarter is the last day of the month after it: Q1 on 30 April, Q2 on 31 July, Q3 on 31 October, Q4 on 31 January.
The income you declare sets the base for the next quarter's contributions. Your Q3 declaration therefore drives the contributions for October, November and December.
The law says income "obtido" in the quarter. It does not say received, and it does not say invoiced. Do not assume either reading when you decide which quarter an invoice belongs to.
Filing is done on Segurança Social Direta.
How the contribution is calculated
Three things decide it: a coefficient applied to your gross income, a rate applied to the result, and a floor and a cap.
The coefficient
Only part of what you invoice counts as relevant income (rendimento relevante). The share depends on the type of income, and each type is declared separately.
| Income type | Share of gross that counts |
|---|---|
| Services (prestação de serviços) | 70% |
| Production and sale of goods | 20% |
| Hotel, restaurant and drinks services, if declared fiscally as such | The same share as goods |
There is no blended rate for a mix. If you bill both goods and services, you declare each total in its own box and each gets its own coefficient.
Expenses do not reduce Social Security relevant income. That is a separate IRS mechanism.
Example (services only): €5,400 of services income in the quarter gives €3,780 of relevant income (€5,400 × 70%).
The rate
The rate for recibos verdes workers is 21.4% of relevant income, whatever you sell. Apart from the exception below, only the coefficient above changes with the type of income.
One exception is worth knowing. An empresário em nome individual who carries on exclusively a commercial or industrial activity, and has declared that to Segurança Social, pays 25.2% instead, from the month of the declaration. Someone who also earns professional services income is not in that case.
Floor, cap and the quarterly adjustment
Floor: on the quarterly path you never pay less than €20.00 a month. The floor is on the contribution. It applies with no income at all, and also when the calculated contribution comes out lower.
Cap: the monthly base cannot exceed 12 times the IAS. At the 2026 IAS of €537.13 (2026) that is €6,445.56 a month.
Adjustment: in the declaration you can move your relevant income up or down by as much as a quarter, in steps of five percentage points. The floor and the cap still apply.
If you are late
A missing Declaração Trimestral is a contraordenação leve. The coima is between 50 and 250 euros under Article 233.º n.º 1 of the Código dos Regimes Contributivos.
You can still file it late, until the end of the month before the next declarative period. Segurança Social Direta shows the route as "Emprego > Trabalhadores independentes > Regime Declaração Trimestral > Consultar Declaração Trimestral".
A late payment owes juros de mora and is a contraordenação. If you cannot pay, you can ask for an acordo de regularização da dívida.
I am not giving the interest rate, the time limits for collection or the conditions of a payment agreement here. Segurança Social's guide does not state them, and I would rather leave them out than guess.
Your benefits are affected too. For the subsídio por cessação de atividade, and for sickness and parental benefits, your contributions must be regularised by the end of the third month before the event. Arrears you clear after you fall ill come too late.
Your first year: enrolled from day one, contributing from month 12
This applies only if you are registering as a trabalhador independente for the first time. What matters is that history, not whether you had a job before. If you worked as an employee and then opened your first self-employed activity, the full deferral applies.
You do not register with Segurança Social yourself. It enrols you automatically from the information AT sends it, and it notifies you. So you are enrolled from the start.
What is deferred is the contribution obligation. Contributions start on the first day of the 12th month after you start your activity. Until then you pay nothing and file no Declaração Trimestral.
When the obligation starts, your base is fixed at a contribution of €20.00 a month, until you file your first Declaração Trimestral. This comes from Article 165.º n.º 1 of the Código dos Regimes Contributivos. It does not depend on what you earn, so it brings a high earner down as well as a low earner up.
A reinício is different. If you have been a trabalhador independente before, you contribute from the first day of the month you restart, with no deferral. The same fixed starting base applies until your first declaration, unless a base is already fixed for that period.
When your client pays a surcharge: entidade contratante
If one client takes more than 50% of your services in a calendar year, that client owes an extra Social Security contribution. You do not pay it. The client does.
The surcharge is 10% where your dependence on that client is above 80%, and 7% in the other cases above the 50% line.
Three conditions apply. The client must be an organisation of any kind (a company, an association or a public body) or an individual with a business activity. You must have been subject to the contribution obligation that year. And your services income must be at least six times the IAS.
Some workers are not counted, including lawyers and solicitors, empresários em nome individual, workers exempt from contributing, and anyone whose income is goods only.
Segurança Social learns who your main clients are from the Anexo SS that you file with your IRS. It asks whether more than 50% of your income came from a single entity and, if so, for each business client's tax number.
What to do this month
- Pay September's contribution between 10 and 20 October.
- File the Q3 Declaração Trimestral by 31 October, with your income for July, August and September.
- Check that no earlier month or interest is outstanding, because direct debit will not collect it.
- If you are in your first twelve months, confirm the date your obligation starts. You may owe nothing yet.
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