Calculate the Nitrogen Oxide (NOx) Levy payable on vehicle registration in Ireland. This charge applies to all petrol and diesel cars registered since 2020.
Verified by VRT Calculator Ireland Research Team
Irish Tax & Import Experts | Updated Feb 2026
NOx tax on diesel cars ranges from €200 to €4,850 (capped maximum), while petrol cars are capped at a maximum of €600. NOx levy uses a three-tier progressive rate system: Band 1 (0-40mg/km) charges €5 per mg, Band 2 (41-80mg/km) charges €15 per mg, and Band 3 (over 80mg/km) charges €25 per mg. Battery Electric Vehicles (BEVs) and hydrogen fuel cell vehicles are completely exempt.
Based on official Revenue.ie VRT rates and valuation methods.
The NOx levy heavily favors petrol and hybrid vehicles. Because diesel engines typically emit higher levels of Nitrogen Oxide, their tax burden is significantly larger, often reaching thousands of Euro for older imports.
Modern Petrol Car: 2021 VW Golf Petrol (32mg/km) — Modern Diesel Car: 2021 VW Golf Diesel (58mg/km).
Pro Tip: The most accurate source for your NOx figure is the Certificate of Conformity (CoC), located in section 1.1 or 1.2 under technical emissions. If importing from the UK, check section V.7 of the V5C. Revenue will not accept generic figures or brochure estimates — they require documented proof from the specific vehicle.
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Open calculator →The NOx (Nitrogen Oxide) levy is an environmental charge applied to vehicles in Ireland based on their nitrogen oxide emissions. Introduced in 2020 to replace the diesel surcharge, it encourages cleaner vehicles by taxing higher-emission cars more heavily. The levy applies to all petrol and diesel vehicles registered since January 1, 2020, and is calculated using a tiered rate system based on mg/km emissions.
NOx tax on diesel cars ranges from €200 to €4,850 (capped maximum). The exact amount depends on your vehicle's NOx emissions. For example: a diesel car emitting 60mg/km would pay approximately €500 ((40×€5) + (20×€15)), while higher-emission diesel vehicles approaching 200mg/km could reach the €4,850 cap. Use our calculator above for your specific vehicle's NOx charge.
Yes, petrol cars registered since 2020 pay NOx levy, but at much lower rates than diesel vehicles. Petrol cars have significantly lower nitrogen oxide emissions and are capped at a maximum of €600, compared to €4,850 for diesel. Most modern petrol cars emit 20-40mg/km NOx, resulting in charges between €100-€400, making them far more affordable than diesel equivalents.
No, NOx levy is a separate additional charge from VRT (Vehicle Registration Tax). Both must be paid when registering a vehicle in Ireland. VRT is calculated based on CO2 emissions and OMSP value, while NOx levy is specifically based on nitrogen oxide emissions. The total registration cost is VRT + NOx Levy + registration fees. Always budget for both charges when importing or registering a vehicle.
NOx levy uses a three-tier progressive rate system: Band 1 (0-40mg/km) charges €5 per mg, Band 2 (41-80mg/km) charges €15 per mg, and Band 3 (over 80mg/km) charges €25 per mg. The calculation is cumulative - you pay the lower rate for the first tier, then higher rates for subsequent tiers. For example, 50mg/km = (40×€5) + (10×€15) = €200 + €150 = €350 total.
No. Battery Electric Vehicles (BEVs) and hydrogen fuel cell vehicles are completely exempt from NOx levy as they produce zero tailpipe emissions. This exemption is permanent and applies to all pure electric vehicles regardless of value or power output. Plug-in hybrid electric vehicles (PHEVs) do pay NOx levy based on their engine's emissions, though typically at lower rates than conventional petrol/diesel cars.
The only way to completely avoid NOx levy is to purchase a pure electric or hydrogen vehicle, or buy a car first registered before January 1, 2020. For newer petrol/diesel vehicles, you cannot avoid the levy, but you can minimize it by choosing cars with lower NOx emissions (check the Certificate of Conformity before purchase). Euro 6d diesel cars typically have lower NOx than older Euro 6 models.
The NOx levy rates and structure remain unchanged in 2026, maintaining the same three-tier system introduced in 2020. The caps also remain at €4,850 for diesel and €600 for petrol vehicles. However, Revenue may update specific rate bands annually, so always verify current rates on Revenue.ie when calculating your total registration costs. This calculator is updated with the latest 2026 Revenue guidelines.
Your vehicle's NOx emissions are found on the Certificate of Conformity (CoC) document under item V.7 or V.9 (measured in mg/km). For UK imports, check the V5C logbook Section V.7. If importing from the EU, the CoC must accompany the vehicle. If you can't locate this figure, contact the vehicle manufacturer or check the vehicle's homologation documentation. Some newer dashboards also display real-time NOx readings.
Older diesel vehicles (particularly Euro 5 and earlier Euro 6 models) pay the highest NOx levy, often reaching the €4,850 cap. High-performance diesel SUVs and commercial vehicles from 2015-2019 frequently have NOx emissions exceeding 150mg/km. The worst offenders include older diesel Mercedes, BMW, Audi, and Land Rover models. Always check NOx figures before importing as the levy can add thousands to registration costs.