How is your home’s IMI calculated in Portugal?

What is IMI?

The Imposto Municipal sobre Imóveis (IMI) is the annual tax on the ownership of property located in Portugal¹. It is owed by whoever owns the property on 31 December of the year the tax relates to, and the revenue goes to the municipality where the property sits. It applies both to urban buildings (such as your home) and to rural buildings (land).

This article (and our IMI calculator) explains the base IMI of a property. The special cases (the AIMI, surcharges and exemptions) are covered further down.

How is IMI calculated?

The IMI calculation is one of the simplest in the Portuguese tax system¹:

IMI = VPT × municipal rate

• The VPT is the property’s taxable value (see the next section).
• The rate is set each year by each municipality, within legal limits.

You can then subtract the family deduction (the "IMI familiar") from that amount, where the municipality grants it. You can estimate it all, with the deduction included, in the IMI calculator.

What is the VPT?

The taxable value (VPT) is the tax value the tax authority assigns to the property and shows on the caderneta predial (which you can view on the Portal das Finanças). It is the basis for IMI.

It is a common pitfall: the VPT is not the purchase price of the home or its market value , it is usually considerably lower. Using the home’s price to work out IMI greatly overstates the tax.

What is the IMI rate in 2026?

The rate depends on the type of building and the municipality¹:

• Urban buildings: each municipality sets the rate each year between 0.3% and 0.45%.
• Rural buildings: a fixed 0.8%.

Because the urban rate is decided locally, two homes with the same VPT in different municipalities can pay different IMI. Always confirm the rate in force in your municipality, it is available on the Portal das Finanças.

What is the IMI familiar?

The IMI familiar is a fixed deduction each municipality may grant on the IMI of a permanent home, based on the number of dependents in the household²:

• 1 dependent → −€30
• 2 dependents → −€70
• 3 or more → −€140

It is optional: not every municipality applies it. It is worth checking with your council whether you qualify, since it is automatic for those the municipality covers.

Worked example

Take a home with a VPT of €150,000, in a municipality with a 0.35% rate:

• IMI = 150,000 × 0.35% = €525.
• As it exceeds €500, it is paid in three instalments (May, August and November).

If the household has 2 dependents and the municipality offers the IMI familiar, €70 is deducted, leaving €455. And, by dropping below €500, it is then paid in two instalments (May and November). Test your case in the IMI calculator.

In how many instalments is IMI paid?

The number of instalments depends on the total amount³:

• Up to €100 → once, in May.
• Between €100 and €500 → two instalments, in May and November.
• Above €500 → three instalments, in May, August and November.

You can always choose to pay it all at once, the billing notice carries the references for that.

What about the AIMI, surcharges and exemptions?

Our calculator covers the base IMI. There are, however, situations that can change it:

• AIMI (Additional to IMI), charged on the sum of the VPTs of residential urban buildings and building land above a per-taxpayer threshold; it is a separate tax from IMI.
• Surcharge on vacant buildings, municipalities may increase the rate on vacant or degraded buildings.
• Exemptions, there is a temporary exemption for the permanent home of lower-income households (subject to VPT and income limits) and permanent exemptions for low-income families¹.

Once you understand IMI, you may be interested in the annual car tax. See how IUC is calculated or, if you sold a property, what capital gains are.