By: Short answer: ISV in Portugal is calculated from three things — engine capacity, CO₂ emissions (WLTP or NEDC) and the age of the car. It does not depend on what you paid for it. Run your exact car through our ISV calculator before you buy — that number decides whether the import is worth it. ISV is paid once; the annual road tax is a separate one, the IUC.
What ISV is and when you pay it in Portugal
ISV (Imposto Sobre Veículos) is Portugal's one-off registration tax. You pay it once, when the car is first registered in Portugal — whether it is new or imported from the EU. It is assessed after the customs declaration (DAV) and must be paid before the Portuguese plate is issued. It is not the IUC, which is the annual road tax you keep paying every year.
If you are still deciding, read whether importing is worth it in 2026 and the full process in how to legalise an imported car in Portugal.
How ISV is calculated: engine component + environmental component
ISV is the sum of two components, each with its own brackets. Every bracket works the same way: (value × rate) − deductible amount.
1. Engine capacity component
| Bracket (cm³) | Rate per cm³ | Deductible |
|---|---|---|
| Up to 1000 | 1,09 € | 849,03 € |
| 1001 to 1250 | 1,18 € | 850,69 € |
| Over 1250 | 5,61 € | 6 194,88 € |
Notice the jump in the third bracket: above 1250 cm³ the rate multiplies roughly fivefold. That is why a 1.2 and a 2.0 with identical CO₂ end up paying very different ISV.
2. Environmental (CO₂) component
The environmental component uses the CO₂ figure from the Certificate of Conformity (CoC), with separate tables for petrol and diesel and for WLTP and NEDC. The brackets are steeply progressive: around 145–146 g/km (petrol, WLTP) the per-gram rate rises sharply. One gram over a bracket can cost several hundred euros — which makes the CoC CO₂ value the single most important number in any listing.
The age reduction — what makes used imports work
For used EU cars the ISV Code applies a reduction by years of use to the tax components. This table is the reason importing makes sense at all:
| Age of vehicle | Reduction |
|---|---|
| Up to 1 year | 10% |
| 1–2 years | 20% |
| 2–3 years | 28% |
| 3–4 years | 35% |
| 4–5 years | 43% |
| 5–6 years | 52% |
| 6–7 years | 60% |
| 7–8 years | 65% |
| 8–9 years | 70% |
| 9–10 years | 75% |
| Over 10 years | 80% |
In practice: the same model at 5 years old pays roughly half the ISV of the 1-year-old version. That is why the 3–5 year band is usually the sweet spot for German imports — see importing a car from Germany in 2026.
Diesel, EVs and plug-in hybrids in Portugal
- Diesel: a €500 surcharge on the total tax, unless the CoC certifies particulate emissions below 0.001 g/km (article 7 of the ISV Code). Check that line on the CoC before you buy.
- Fully electric: exempt from ISV.
- Plug-in hybrids: pay a reduced share of the ISV, but only if they meet the legal conditions on minimum electric range and maximum emissions. The CoC is what proves it — "it's a hybrid" is not enough.
The mistakes that cost money
- Using the CO₂ from the advert instead of the CoC. German listings mix figures; only the CoC counts for customs.
- Confusing WLTP with NEDC. WLTP gives higher values and can push the car one bracket up — a difference of hundreds of euros on the same model.
- Counting only the ISV. On top of it come the category-B inspection, IMT homologation, DUA and registration, plus transport. Compare the registered total against the Portuguese price, never the sticker.
To avoid doing this by hand on every listing, our browser extension shows the ISV estimate right on the German dealer's page. And if you would rather it were simply handled, we import and legalise the car end to end.
Note: Clara Cars is an independent car sourcing and import service — not the tax authority and not a bank. The tables above are those of the ISV Code (Law 22-A/2007) as applicable in 2026 and are for estimating; the amount due is the one from the official assessment for the specific vehicle. Always simulate before you sign.
Frequently asked questions
How do I calculate ISV on an imported car in 2026?
You need four figures from the CoC: engine capacity in cm³, CO₂ emissions, homologation standard (WLTP or NEDC) and the date of first registration. Feed those into the ISV calculator for an instant estimate.
Does ISV depend on the price of the car?
No. ISV depends on engine capacity, CO₂ and age. Two cars with the same price can owe very different ISV, and a cheaper car can owe more tax.
What is the difference between ISV and IUC?
ISV is paid once, at registration. The IUC is paid every year, in the anniversary month of the registration. Separate taxes, separate calculations.
Do electric cars pay ISV in Portugal?
No. Fully electric vehicles are exempt from ISV. Plug-in hybrids can qualify for a reduced rate if they meet the legal range and emissions conditions.
Can I be exempt from ISV if I move to Portugal?
There is a transfer-of-residence exemption, subject to conditions on how long you owned the car, timing and proof of previous residence. It has to be checked case by case — and it covers ISV only, not the annual IUC.