Vehicle Registration Tax 2026 – ISV Simulator

The Portuguese vehicle tax is paid once only, when a vehicle is registered in Portugal for the first time. That is why it is known as the registration tax, and why it should not be confused with IUC, the annual road tax that follows the car for as long as it is in your name.

It is paid by whoever releases the vehicle for consumption. On a new car bought at a dealership, ISV is already built into the price and the brand importer settles it. If you are the one bringing a used car in from France or Germany, you are the taxable person: you file the customs vehicle declaration and pay the tax before you can get Portuguese plates.

If you are buying a used car that already carries a Portuguese plate, you do not pay ISV again — it was settled when the car first went on the road here. The bill only comes back if you are the one bringing a vehicle in.

• What pushes the tax up: engine size, CO₂ emissions and, on diesel light vehicles, the lack of a low enough particulate figure.
• What brings it down: years of use (only on vehicles brought in used), the intermediate rates for plug-in hybrids and natural gas and, at the limit, the fact that electric vehicles are out of scope.
• What counts for nothing: the price you paid. Two cars with the same engine and the same emissions pay exactly the same ISV, whether they cost €8,000 or €40,000.

On passenger cars, the table A tax is the sum of two parts worked out the same way: rate × value − deductible amount. The engine-size component uses the cc of the engine. The environmental component uses CO₂ emissions in g/km, on the table for the fuel (petrol or diesel) and the homologation cycle (WLTP or NEDC).

With real numbers: a new petrol car of 1598 cc with 139 g of CO₂/km under WLTP. Engine-size component: 5.61 × 1598 − 6,194.88 = €2,769.90. Environmental component: 6.38 × 139 − 762.73 = €124.09. ISV due: €2,893.99.

When the environmental component comes out negative — which happens on very efficient cars — that figure is deducted from the engine-size component instead of being clamped to zero. It is a detail several simulators ignore, and it changes the total.

• 1. Add the components: engine size plus environmental on table A, engine size only on table B for vans and motorhomes.
• 2. Vehicle-type percentage: if the vehicle meets the conditions, the sum is multiplied by a table A intermediate rate — 60 %, 40 % or 25 % — or by the table B percentage that matches the body type: 10 %, 15 %, 50 %, or 80 % on motorhomes through 2026 (100 % from 2027).
• 3. Age-based reduction: only on vehicles brought in used, from 10 % to 80 % depending on age.
• 4. Particulate surcharge: an extra €500 on diesel light vehicles that do not stay below 0.001 g/km — and that amount sits inside the age reduction.
• 5. Minimum tax: on tables A and B the total never falls below €100.

That is the order the simulator applies, and the order the tax authority follows when it assesses the customs declaration.

ISV has no month of its own in the calendar, unlike IUC. It falls due once, when the vehicle is registered in Portugal for the first time, so the practical form of the question "when do I pay" is "when do I bring it in". What runs the clock is the customs vehicle declaration (DAV): it is its filing deadline that the law counts, and its date that fixes the rates.

Start by checking whether any of this is yours to do. On a new car bought at a dealership there is no deadline for you to meet: the ISV is already inside the price you signed for, the brand importer files the declaration and settles the tax, and no notification from the tax authority ever reaches you. On a used car that already carries a Portuguese plate, the same: the tax was settled at the first registration and there is no second one. The deadlines below belong to whoever brings a vehicle in from abroad and registers it in their own name.

There are two deadlines in sequence, and only the first one is up to you: 20 working days from the vehicle entering national territory to file the DAV and then, once the assessment is notified, 10 working days to pay the amount the tax authority has worked out. In between sits the time the assessment takes, which you do not control — the deadline you have to protect is the first.

The date of the DAV counts twice, and this is where most people get it wrong. The rates applied are the ones in force on the day you file it — not those of the day you bought the car, nor those of the day it arrived. The age of the vehicle for the age-based reduction, on the other hand, is not counted to that day: it is counted to the end of the filing deadline, whether you file on the first day or on the last. Waiting a few more weeks for the car to grow older and jump a band on table D changes the reduction not at all — all it changes is that the filing is now late, and late filing carries a penalty.

It is also the date of the DAV that decides which side of the year end the process falls on: a declaration filed in the last days of December is assessed on the tables of that year, one filed in the first days of January on the tables of the next. On motorhomes that is money in plain sight — between the 80 % of table B in 2026 and the 100 % that starts in 2027 there is €3,326.40 on the 2287 cc one from the block above.

• Day zero — entry into national territory. That is where the 20 working days start running, not the invoice date and not the date of the contract.
• Within the deadline — the DAV. The day you file it fixes the rates; the age of the vehicle, by contrast, always counts to the end of the deadline.
• After the notification — 10 working days to pay. The amount is whatever the tax authority assesses from the homologation data, and it may not be exactly the one in the simulation.

Two details that make a difference in practice: the deadlines are counted in working days, so 20 working days come to close to four calendar weeks — and more if public holidays fall inside them — and day zero is the day the vehicle enters national territory, not the day you paid the seller. If you bought the car in one month and it only arrived the next, it is the arrival that counts.

Anyone bringing a vehicle into the country has to declare it to customs before registering it. That is done with the customs vehicle declaration (DAV), filed electronically in the customs area of the Portal das Finanças — or handled by a customs agent, if you prefer to hand the process over.

The deadline is 20 working days from the vehicle entering national territory. Once the tax authority issues the assessment, you have 10 working days from the notification to pay. The rates applied are those in force on the date of the declaration, and it is the end of that same deadline that fixes the vehicle age used for the reduction.

With the ISV paid, next come the roadworthiness test for plate assignment and the registration request at IMT, with 60 days to pay the fee and ask for the certificate. Keep the certificate of conformity, the invoice or bill of sale, and the proof of the declaration: those documents back up the engine-size and CO₂ figures you used in the simulation.

• Before buying: simulate the ISV with the engine size and CO₂ shown in the listing — it is the largest slice of the cost of bringing a car in.
• Before shipping the car: confirm those figures on the homologation. One gram of CO₂ can change the band, and the difference runs into hundreds of euros.
• After it arrives: count the 20 working days from entry into national territory and file the declaration within the deadline.

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