Paying the IMI Municipal Property Tax in Portugal in 2026 — A Practical Guide to Taxable Property Values, the 0.3%–0.45% Municipal Rates, the May–August–November Instalments, the Low-Income and Own-Home Exemptions and the AIMI Surcharge

If you own property in Portugal — an apartment in Lisbon, a village house in the interior, a plot of land you are sitting on — you will meet the Imposto Municipal sobre Imóveis (IMI – Municipal Property Tax) every year. It is the annual tax that funds your município (municipality), it lands in instalments across the second half of the year, and it is one of the few Portuguese taxes that arrives without you having to file anything: the Autoridade Tributária (AT – Tax Authority) calculates it and sends you the bill. This is a practical 2026 guide to how IMI is worked out, who pays and when, the exemptions worth knowing about, and the extra tax that kicks in on higher-value estates.

What IMI is and how it is calculated

IMI is a tax on the ownership of real estate, charged on the property's Valor Patrimonial Tributário (VPT – taxable asset value) rather than its market price. The VPT is the figure the AT assigns to each building or plot, and for most homes it is comfortably below what the property would sell for. It is set by a formula that weighs a base value against the property's area, its use, its location, its quality and comfort, and its age — the older the building, the lower the coefficient, and therefore the VPT. You can look up the VPT of anything you own on the Portal das Finanças, and if you think it is too high (for example after the building has aged or deteriorated), you can request a fresh avaliação (valuation) — generally once every three years.

The tax you pay is the VPT multiplied by your municipality's IMI rate. The rate is not the same everywhere, and that is the point of a municipal tax:

• Urban buildings (prédios urbanos — homes, shops, offices): each municipality sets its own rate every year within a legal band of 0.3% to 0.45%. City councils vote the figure and communicate it to the AT; many larger councils sit at or near the 0.3% floor to stay competitive.
• Rural land (prédios rústicos): a fixed rate of 0.8%.
• Property held via tax havens: buildings owned by entities resident in blacklisted jurisdictions are hit with a punitive 7.5% rate.

So a €120,000-VPT flat in a municipality charging 0.3% generates €360 of IMI a year; the same flat where the council charges 0.45% generates €540. It is always worth knowing which rate your câmara municipal has set.

Who pays, and when

The taxpayer is whoever owns the property — or holds the usufruto (usufruct) or a surface right over it — on 31 December of the year in question. If you buy in January, last year's IMI was the seller's; your first bill arrives the following year. The AT notifies you of the amount by around 30 April, by post or through your electronic tax mailbox, and payment then falls due in instalments whose number depends on the size of the bill:

• Up to €100: a single payment, due in May.
• €100.01 to €500: two instalments, in May and November.
• Over €500: three instalments, in May, August and November.

You can always choose to pay the whole amount in the first instalment if you prefer to be done with it. A practical 2026 note: the May deadline formally falls on 31 May, but because that date is a Sunday this year, it rolls to the next working day. Miss an instalment and the full outstanding balance can become immediately payable, with interest — so it is worth setting a reminder or, better, a direct debit.

How to pay

Everything runs through the Portal das Finanças. Log in, find the IMI note under your Património (assets) area, and you will see a payment reference (a Documento Único de Cobrança, or DUC) for each instalment. You can then pay by Multibanco or home banking using that reference, at an ATM, at a CTT post office or Finanças counter, or set up débito direto (direct debit) so each instalment is collected automatically on its due date — the surest way not to trip the missed-instalment rule. If you do not yet have a tax number, that is the very first step for any property owner; see our guide to getting a Portuguese NIF.

The exemptions worth knowing

Two IMI exemptions matter most for residents, plus a family discount your council may or may not offer:

• Permanent low-income exemption: households whose gross annual income does not exceed 2.3 times the annual Indexante dos Apoios Sociais (IAS – the social-support reference index) — roughly €17,300 in 2026 — and whose home has a VPT no higher than about €67,260 are permanently exempt on their own permanent residence. The AT is meant to apply this automatically when you qualify.
• Temporary own-home exemption: when you buy or build a property as your own permanent residence, you can claim a time-limited exemption (historically up to three years) provided the VPT sits below the legal ceiling and you have no debts to the state or Social Security. You must request it, generally within 60 days of establishing the address as your domicílio fiscal (tax residence). A 2023 change (Lei 56/2023) lets individual municipalities extend this by a further two years if they choose.
• IMI Familiar (family deduction): municipalities may — it is optional — grant a fixed annual deduction to households with dependent children: commonly €20 for one child, €40 for two and €70 for three or more. Whether you get it depends entirely on whether your council has opted in.

Because these thresholds are indexed and the family discount is a local choice, confirm the current figures and your municipality's decisions rather than relying on last year's numbers.

AIMI: the surcharge on larger estates

On top of ordinary IMI, higher-value property portfolios attract the Adicional ao IMI (AIMI – the additional to IMI), Portugal's mild version of a wealth tax on real estate. It is charged on the combined VPT of the residential buildings and building land a person owns, above a personal allowance of €600,000 (couples who opt to be assessed jointly share a combined €1.2 million allowance). For individuals the rates run at 0.7% on the value above the allowance, rising to 1.0% on the slice between €1 million and €2 million and 1.5% above €2 million; companies pay a flat 0.4%. Commercial, industrial and services buildings, and rural land, are left out of the AIMI base — so it bites mainly on substantial residential holdings.

A few practical habits

• Check your VPT once a year. It drives every euro of IMI (and AIMI). If your building has aged past a coefficient band, a re-valuation can lower the bill.
• Know your council's rate. The difference between 0.3% and 0.45% is 50% more tax on the same property; it is public information.
• Set up direct debit. It removes the risk of a missed instalment turning the whole year's tax immediately due.
• Keep IMI in your buying maths. When you weigh a purchase, factor the annual IMI — and, on a larger place, any AIMI — into the running cost, the way you would with the condomínio and insurance.

This guide is general information, not tax advice. IMI rates, exemption thresholds and the IAS-linked limits are set annually and vary by municipality; confirm the figures that apply to your property on the Portal das Finanças or with a Portuguese contabilista certificado (certified accountant) before acting.