How ISV is calculated in Portugal
ISV (Imposto Sobre Veículos) is a one-off tax paid when you register/import a car. It combines an engine-size component with an environmental (CO₂) component, reduced by the vehicle's age. Here is the calculation, step by step — and the code is open, so you can verify it.
Step by step
- Engine-size component — a rate per cm³ from Tabela A (progressive brackets).
- Environmental (CO₂) component — a rate by emissions; WLTP for recent cars, NEDC for older ones (by registration year).
- Age reduction — used cars get a percentage reduction on the total, by years since first registration.
- Particulate surcharge — €500 for diesels emitting ≥0.001 g/km (with its own age reduction).
- Special cases — plug-in hybrid (≥50 km electric + low CO₂ → 75% reduction), fully electric (exempt), motorhomes/motorcycles/commercials (Tabelas B/C/D).
See it with an example
Open this example in the calculator →
Sources & verification
Based on the official Autoridade Tributária (AT) tables, cross-checked June 2026. It's a maintained estimate — not a substitute for the official AT simulator or a despachante. The calculation is open source (MIT): github.com/claracarspt/calcs.
Import tax (ISV) · How IUC is calculated in Portugal · ISV & IUC