Handytool
Car tax guide5 min readUpdated Mar 20, 2026

Free ISV Estimate

Estimate Portugal ISV Before You Legalize Your Car

The Portugal ISV Calculator combines the displacement component, the environmental CO2 component, the diesel particle surcharge, and the used-import age reduction to give you an instant 2026 estimate — all in your browser.

Key takeaways

  • 01ISV (Imposto Sobre Veículos) combines an engine displacement component and an environmental CO2 component, with different tables for petrol and diesel cars.
  • 02Diesel cars with qualifying particulate emissions can incur a 500 EUR surcharge on top of the base ISV.
  • 03Used imports from EU countries receive an age-based reduction applied to the calculated ISV.
  • 04Pure electric passenger cars are generally exempt from ISV, but always verify against current official conditions.

What Is Portuguese ISV and Who Pays It?

ISV, or Imposto Sobre Veículos, is the Portuguese vehicle registration tax. It is due whenever a passenger car is first registered in Portugal — whether you are buying a new car locally, importing from another EU member state, or bringing in a vehicle from outside the EU. The tax is not a one-size-fits-all flat rate; it is built from several components that interact with each other, which is why a calculator that shows the breakdown is genuinely useful.

The main components for a 2026 passenger car are: a cylindrical displacement component assessed against the engine size in cc, and an environmental component based on WLTP CO2 emissions in g/km. Diesel vehicles with measurable particulate emissions above the threshold can attract a 500 EUR surcharge. For used vehicles imported from the EU, Portuguese law applies a progressive age-based reduction to the calculated ISV, so older cars often pay significantly less than a new equivalent.

How to Use the Portugal ISV Calculator

Run the estimate in seconds — no account, no data upload.

  1. 01

    Enter engine displacement

    Input the engine cylinder capacity in cubic centimetres (cc) from the vehicle's registration document or CoC. This drives the displacement component of ISV.

  2. 02

    Enter WLTP CO2 emissions

    Type the official WLTP CO2 value in g/km. For older vehicles that were certified under NEDC, use that figure. The CO2 value feeds the environmental component.

  3. 03

    Select fuel type

    Choose petrol, diesel, hybrid, or electric. Diesel triggers the diesel-specific CO2 table and may include the particle surcharge check.

  4. 04

    Enter first registration year

    For used imports, enter the year of first registration. The calculator applies the age-band reduction percentage to estimate the payable ISV.

  5. 05

    Review the line-by-line breakdown

    See the displacement component, environmental component, any particle surcharge, the age reduction applied, and the estimated total ISV payable.

Documents to Have Handy Before Calculating

Find these figures on the vehicle's Certificate of Conformity, EU registration certificate (V5 equivalent), or manufacturer data sheet:

  • 01Engine displacement in cc (cylinder capacity)
  • 02Official WLTP CO2 emissions in g/km
  • 03Fuel type (petrol, diesel, plug-in hybrid, or pure electric)
  • 04Year of first registration (for age-based reduction on used imports)
  • 05Particulate value if available (for diesel vehicles)

Browser-Only Calculation — Your Data Stays Private

Handytool runs the ISV estimate entirely in your browser. No vehicle identification, no personal data, and no prices are sent anywhere. You can bookmark the page and return to it as you compare different vehicles.

The calculator applies the 2026 passenger-car tables for displacement and the environmental CO2 component. Because the official Portal das Finanças simulator uses the precise legal tables and may incorporate administrative factors not available publicly, treat this result as a planning estimate. For the definitive ISV value required for legalization, use the official simulator or consult a licensed despachante (customs agent) in Portugal.

Portugal ISV Calculator FAQ

How is ISV calculated in Portugal?

Passenger-car ISV combines an engine displacement component and an environmental CO2 component. Different tables apply to petrol and diesel cars, and a diesel particle surcharge may be added where applicable.

Do used imports pay less ISV?

Yes. EU used imports are entitled to an age-based reduction that increases with the vehicle's age. The calculator applies the standard reduction band based on your entered first registration year.

Do diesel cars pay extra ISV?

Diesel passenger cars with particulate emissions at or above the threshold can pay a 500 EUR surcharge on top of the base ISV amount.

Are electric cars exempt from ISV?

Pure electric passenger vehicles are generally exempt from ISV. Always verify against the current official conditions, especially for plug-in hybrids, which follow a different calculation.

Is this the official Portal das Finanças simulator?

No. This is an independent browser-only planning estimate based on public 2026 tables. Use the official AT simulator for the figure required for legalization.

Can I use this for a car imported from outside the EU?

The ISV calculation logic is the same regardless of origin, but non-EU imports may also be subject to customs duties handled separately. The calculator covers ISV only.

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