What happens if you do not declare income in Portugal
A guide for people living in Portugal who have left part of their income out of their tax return or are planning not to declare it. We explain when income has to be shown, how to correct a return and what discrepancies with bank and tax data can lead to.
Work out whether you have to declare income in Portugal
First establish your tax residence for the calendar year in question. You are usually treated as a Portuguese resident if you spent more than 183 days here in a 12-month period starting or ending in that year, or had a home that shows you intended to use it as your habitual residence. Special rules are also taken into account, so registering an address is not enough on its own.
A tax resident usually declares worldwide income in Portugal: salary, work for foreign clients, rent, interest, dividends, securities transactions and other income. A non-resident, as a rule, shows only income from Portuguese sources. An exemption from tax, or tax already paid in another country, does not always release you from the obligation to show the income itself.
Reconstruct your real income, not just what came into your card
Gather contracts, invoices, recibos verdes (the self-employed's electronic receipts), and bank and brokerage statements. Separate income from transfers between your own accounts, refunds, loans and currency exchange: money moving does not always count as income in itself.
If a client paid through a platform, the income is often taken to be the full amount paid by the client, while the platform's fee is accounted for separately — if your tax regime allows expenses to be taken into account. You cannot automatically declare only the amount left after the fee.
Check your return and the annexes you need
The Modelo 3 de IRS (the annual income tax return) is filed through the Portal das Finanças (the tax portal) from 1 April to 30 June of the year after the tax year. Foreign salaries, pensions, interest, dividends and other income from abroad usually go in Anexo J (the annex on foreign income). Self-employed activity goes in Anexo B or Anexo C, and capital gains in Anexo G or Anexo J, depending on the source.
In Anexo J also check the section on foreign bank and investment accounts. Listing an account does not replace declaring the income, and declaring the income does not remove the obligation to report details of the account, if it applies to your situation.
Correct the omission voluntarily
If you have already filed a return, submit a declaração de substituição (a replacement return) through the Portal das Finanças. If you did not file one, file it late. After recalculating, the Autoridade Tributária e Aduaneira (the tax and customs authority) may charge additional tax, juros compensatórios (compensatory interest) and a fine.
Correcting voluntarily before an audit starts is usually better than waiting to be asked: the law allows the fine to be reduced depending on when you correct and whether an inspection had already begun. Keep the confirmation of submission and the new tax assessment.
Additional tax can also be paid in instalments: it has its own bill and its own deadline, and after that the same 15 days to ask for a payment plan. This matters: while the payment plan is approved and you keep paying it, your tax position counts as “in order”, the certificate of no debts comes out clean and you can demand to be removed from the public list of debtors.
Be ready for a request from the tax office or the bank
Portugal takes part in CRS, the automatic exchange of financial information. What is usually passed on is the account holder's identification details, tax number, the balance or value of the account and certain types of income — for example, interest, dividends and proceeds from selling financial assets. This does not mean the tax office knows in advance what each transfer was for, but it can ask for statements and explanations.
Do not ignore a notificação (an official notice). Reply by the deadline it gives, attaching statements, contracts and a calculation explaining transfers between your own accounts. The absence of automatic data does not release you from filing a return, and automatic exchange does not remove the tax office's right to ask for documents directly.
The bank separately checks the origem dos fundos (source of funds) under anti-money-laundering rules. If you cannot explain regular or large payments in, it may hold up a transaction, restrict your account or end the relationship — whether or not a tax audit has started.
Weigh up the possible consequences
For not filing a tax return, or filing it late, the RGIT (the regime of tax offences) sets a fine of €150 to €3,750. This is the statutory range in force for 2026; the actual amount depends on the circumstances, voluntary correction and whether tax is owed. The tax and interest are added on top. If you do not pay, the debt can go to execução fiscal (enforced tax collection), including seizure of money or property.
If the authorities believe the income was hidden deliberately, the case can be more serious than an ordinary mistake. Under Article 103 RGIT, tax fraud becomes a criminal offence when the unlawful tax advantage exceeds €15,000 on the return concerned; this is the legal threshold for 2026. Aggravated fraud and other offences have their own conditions and penalties.
The usual period for charging additional tax is generally four years, but in some cases it is longer. For certain undeclared foreign accounts or transactions linked to jurisdictions on Portugal's list of preferential tax regimes, the period can be up to 12 years.
Do not confuse your tax return with proof of funds for a residence permit
AIMA (the Agency for Integration, Migration and Asylum) may ask for proof of means of subsistence when issuing or renewing some types of residence permit. No income on your IRS does not always mean an automatic refusal: what counts as proof depends on the grounds for the residence permit and may include a contract, recibos de vencimento (payslips), money in the bank or a sponsor's income.
But a mismatch between the income declared to AIMA, your tax return and the payments into your bank account may lead to a further request. A forged certificate or knowingly false information is more dangerous than an honest explanation of the omission and a corrected return.
Check your obligations to Russia separately
A Portuguese return does not replace your Russian obligations. If under Russian rules you are still a tax or currency resident, check separately the notifications of foreign accounts, the report on cash flows (ODDS) and the 3-NDFL return (the Russian personal income tax return). These are three different obligations: reporting an account is not the same as reporting on it, and neither is the same as declaring income.
Do not rely on automatic exchange to confirm your turnover or the absence of income by itself. The Russian tax service may ask for bank statements even when a person believes they are exempt from the annual ODDS. The rules, lists of countries and exceptions change, so they need to be checked for the specific reporting year.
Get help if an audit has already started
If you have received an audit report, a large additional tax bill or a suspicion of deliberate concealment, do not stop at a verbal explanation. Ask a contabilista certificado (a certified accountant) to rebuild the calculations, and an advogado fiscal (a tax lawyer) to check the deadlines and how to appeal.
Send a written reply through the Portal das Finanças or in the way stated in the notice. Do not send corrections blindly: first compare your returns, accounts, statements and the taxes already paid abroad, so that you do not declare internal transfers as new income.
What changed
- 28 August 2026 — added that additional tax can be split into payments and that a payment plan keeps your certificate clean
- 26 August 2026 — added readers' stories
What to bring
- NIF (Portuguese tax number)
- access to the Portal das Finanças (the tax portal)
- Modelo 3 de IRS and the annexes filed
- bank statements for all related accounts
- brokerage reports and income certificates
- employment contracts and payslips
- contracts with clients and platform reports
- recibos verdes (the self-employed's receipts)
- rental contracts and proof of payments
- certificates of tax paid abroad
- notices from the tax office, AIMA or the bank
- proof of transfers between your own accounts
Where people most often trip up
- Thinking foreign income need not be shown if the money was not transferred to Portugal.
- Confusing bank turnover with taxable income.
- Declaring income after the platform's fee instead of the full amount from the client.
- Not declaring exempt income, even though it still has to be shown.
- Hoping that no data in CRS means no obligation to declare.
- Ignoring a request because the system has already accepted the return.
- Confusing the Portuguese return with the Russian report on cash flows in foreign accounts (ODDS).
- Not keeping proof of tax paid in another country.
- Filing a correction without checking transfers between your own accounts.
- Giving AIMA information that does not match your IRS and bank statements.
How it went for people
Fines for other people's rental cars on her NIF
A woman saw a €130 fine in her Finanças personal area and paid it straight away, thinking it was for speeding. Then a second one came, for €168, and she asked via e-balcão what it was for: it turned out to be for driving on the A22 toll motorway in December 2024 in rental cars she had neither hired nor driven — but her tax number had been linked to them. The Finanças demanded that she prove it was not her; for four months the rental firms replied that they would “look into it” and then went quiet. So she booked an appointment at the office: there, in front of her, they saw within a couple of minutes that the cars were not registered to her, but she had to write a full-page statement on the spot by hand — she was not allowed to print it. Two weeks later the unpaid fine was cancelled.
The landlady dragged her feet over the contract — and the proof of residence could not be obtained
A woman rented a flat, and the landlady warned her straight away that there would be no contract at first. Several months later nothing had moved, and the tenant herself suggested leaving things as they were. In January she really needed the contract, but only in March did the landlady pass on, through other people, a document in which the tenancy began on 1 April and at a higher rent. The junta de freguesia (parish council) would not issue proof of residence on that document — the address in the contract was wrong — and for weeks the landlady did not answer requests to register the contract with the Finanças. In the end the tenant wrote that she did not need such a contract, went back to paying in cash and started sorting out her address another way.
A letter from the Finanças: did you have income and accounts abroad?
In May a man received a letter from the Finanças asking whether he had had income and accounts abroad in 2025. He had listed the accounts in his IRS return, and the return had already been accepted. He had indeed had income abroad that year, but only before he became a Portuguese tax resident, that is, before he changed the address on his NIF; after that there was no foreign income. It came down to how to word the reply: there are accounts abroad, but there was no income while he was resident.
Retold in our own words from messages in open chats. The link leads to the full original message.