How VRT Is Calculated in Ireland
A clear, step-by-step explanation of the Vehicle Registration Tax formula used in Ireland — from OMSP to final bill, with worked examples for every scenario.
The VRT Formula
Vehicle Registration Tax in Ireland is calculated using a four-part formula. Every component matters, and a mistake in any one part can cost you hundreds or thousands of euro. Here is the complete formula broken down into its essential elements:
Let's break that down. OMSP is the Open Market Selling Price — the realistic value of the vehicle in the Irish market. Band Rate is a percentage that depends on the vehicle's CO₂ emissions output. The NOx Levy is an additional charge that applies only to diesel vehicles. Age Reduction lowers the base VRT amount for older vehicles, and EV Relief is a deduction available for qualifying electric vehicles.
The formula is applied in a specific order. First, you calculate the base VRT by multiplying the OMSP by the CO₂ band rate. Then you add the NOx levy for diesel vehicles. From that subtotal, you subtract any age reduction factor. Finally, you deduct any EV relief if applicable. The result is the total VRT you owe Revenue. Understanding the order of operations matters because the age reduction applies to the base VRT only — it does not reduce the NOx levy.
Step 1: Determine the OMSP
The Open Market Selling Price is the foundation of your VRT calculation. OMSP is defined by Revenue as the price at which the vehicle would be sold in the open market in Ireland under normal conditions, including all applicable taxes. It is not the price you paid for the vehicle abroad. It is not the replacement cost of a new vehicle. It is the realistic selling price of that specific used vehicle in the Irish market as if it were on a dealer's forecourt today.
Revenue takes OMSP valuations extremely seriously because undervaluation is the most common form of VRT fraud. If you declare an OMSP of €10,000 but Revenue believes the true market value is €15,000, they will issue a reassessment for the additional tax plus interest at approximately 8% per year. In cases of deliberate undervaluation, penalties of up to 100% of the underpaid tax can apply on top of the interest. This makes accurate OMSP declaration critical.
How to Establish a Defensible OMSP
There are several reliable methods to determine a defensible OMSP figure. The most straightforward is to check current Irish dealer prices for vehicles of the same make, model, year, and comparable mileage. Online platforms such as DoneDeal, Carzone, and manufacturer-approved used car programmes provide real market data. Revenue also publishes its own OMSP tool on the Revenue Online Service (ROS), which provides indicative values based on make, model, and specifications. While the Revenue OMSP tool is not binding, it gives you a clear indication of what Revenue considers a reasonable value.
If you are importing a vehicle that is not commonly sold in Ireland — for example, a specialist import or a model not officially distributed here — you may need to provide evidence of value from the country of origin. Revenue may accept dealer quotes, auction results, or independent valuations. The key is to be able to justify your declared OMSP with documentary evidence if challenged. Our OMSP calculator helps you estimate your vehicle's OMSP using current Irish market data.
Step 2: Find Your CO₂ Emissions
Once you know the OMSP, the next step is to determine the vehicle's CO₂ emissions figure. This number, measured in grams per kilometre (g/km), determines which VRT band your vehicle falls into and therefore what percentage rate is applied to the OMSP. The CO₂ figure is taken from the vehicle's Certificate of Conformity or type approval documentation, which should have been supplied with the vehicle when it was originally sold.
NEDC vs WLTP — Which Standard Applies?
Ireland has transitioned from the older NEDC (New European Driving Cycle) test standard to the newer WLTP (Worldwide Harmonised Light Vehicles Test Procedure). Vehicles first registered before September 2018 may have NEDC-tested CO₂ figures, while vehicles registered after that date generally use WLTP figures. Revenue uses the official test figure that corresponds to the vehicle's date of first registration. You cannot choose the more favourable figure — you must use the standard that applies to your vehicle's registration date.
WLTP figures are generally higher than NEDC figures for the same vehicle because the WLTP test is more realistic and demanding. This means a vehicle that appeared to fall into a lower band under NEDC may move to a higher band under WLTP. If you are comparing vehicles, make sure you are comparing like-for-like test standards. The CO₂ figure on the Certificate of Conformity is the definitive number that Revenue will use.
VRT CO₂ Band Table (2026)
| Band | CO₂ Emissions (g/km) | VRT Rate |
|---|---|---|
| A | 0 – 60 | 0% |
| B | 61 – 110 | 10.1% |
| C | 111 – 140 | 15.6% |
| D | 141 – 155 | 20.1% |
| E | 156 – 170 | 24.6% |
| F | 171 – 190 | 29.1% |
| G | 191 – 225 | 34.6% |
| H | 226+ | 40.6% |
Using the table above, find the row where your vehicle's CO₂ figure falls. A car emitting 135g/km falls into Band C (111–140 g/km) and attracts a 15.6% VRT rate. A car emitting 230g/km falls into Band H (226+ g/km) and attracts a 40.6% rate. The difference between bands is significant — a €20,000 OMSP car in Band C costs €3,120 in base VRT, while the same car in Band H costs €8,120. Choosing a lower-emission vehicle is the single most effective way to reduce your VRT bill.
Step 3: Apply the VRT Band Rate
With the OMSP determined and the CO₂ band identified, the next step is straightforward multiplication. Multiply the OMSP by the band rate percentage to get the base VRT amount. For example, if your vehicle has an OMSP of €25,000 and falls into Band D (20.1%), the base VRT is €25,000 × 0.201 = €5,025.
This base VRT amount is before any adjustments. The age reduction factor, NOx levy, and EV relief are all applied separately. Getting the base rate right is essential because errors here cascade through the rest of the calculation. Always double-check the band rate against the current Revenue table, as rates can change with each Budget.
Age Reduction Factor
Ireland applies an age reduction factor to the base VRT for vehicles that are more than 12 months old at the time of first registration in Ireland. This recognises that older vehicles have depreciated and should not be taxed at the same level as a new vehicle. The reduction percentages are as follows:
| Vehicle Age | Reduction |
|---|---|
| Up to 1 year | 0% (no reduction) |
| Over 1 year but not more than 2 years | 10% |
| Over 2 years but not more than 3 years | 20% |
| Over 3 years but not more than 4 years | 30% |
| Over 4 years but not more than 5 years | 40% |
| Over 5 years but not more than 6 years | 45% |
| Over 6 years | 50% |
The age reduction applies only to the base VRT amount — it does not reduce the NOx levy for diesel vehicles. This is a critical distinction. A four-year-old diesel car gets a 30% reduction on the base VRT but still pays the full NOx levy. This can make older diesel vehicles significantly more expensive to register than they first appear.
Step 4: Calculate the NOx Levy
The Nitrogen Oxide (NOx) levy is an additional charge that applies specifically to diesel vehicles when they are registered in Ireland. Introduced in Budget 2020, the levy targets the air quality problems caused by diesel exhaust emissions, particularly nitrogen dioxide (NO₂) which contributes to smog and respiratory health issues in urban areas. The levy is calculated separately from the main VRT charge and is based on the vehicle's NOx emissions measured in milligrams per kilometre (mg/km).
The NOx levy applies to all diesel-powered vehicles regardless of age, meaning even a five-year-old diesel car that benefits from a 40% age reduction on its base VRT will still pay the full NOx levy. Petrol vehicles, hybrid vehicles, and fully electric vehicles are completely exempt from the NOx levy. The levy amount is capped at €4,800 for passenger cars.
How the NOx Levy is Calculated
The NOx levy uses a sliding scale formula based on the vehicle's NOx output in mg/km. Cleaner diesel vehicles with lower NOx figures pay less, while dirtier vehicles pay more up to the cap. Euro 6 diesel vehicles typically have lower NOx figures and therefore lower levies, while older Euro 5 or Euro 4 diesel vehicles attract significantly higher charges. The NOx figure is taken from the vehicle's Certificate of Conformity or type approval documentation. If no official figure is available, Revenue may apply a default value based on the vehicle's engine size and Euro standard.
For anyone considering importing a diesel vehicle, the NOx levy is a critical factor in the total cost calculation. A vehicle that appears cheap to import based on VRT alone may become expensive once the NOx levy is added. Use our NOx calculator to determine the exact levy for your specific vehicle before you commit to an import purchase.
Worked Example 1: Irish-Registered Car
Let's walk through a complete VRT calculation for a vehicle that was originally registered in Ireland and is being transferred to a new owner. Note that VRT is only paid once when a vehicle is first registered in Ireland — a second-hand Irish-registered car does not attract VRT again. However, understanding the original calculation helps you understand what was paid and why.
Vehicle: 2022 Volkswagen Golf 1.5 TDI, 118 g/km CO₂, diesel, OMSP €22,000
Step 1: Identify the Band
CO₂ emissions of 118 g/km fall into Band C (111–140 g/km). The band rate is 15.6%.
Step 2: Calculate Base VRT
€22,000 × 15.6% = €3,432
Step 3: Calculate NOx Levy
This is a Euro 6 diesel with NOx emissions of 80 mg/km. Using the Revenue NOx levy formula, this attracts a levy of approximately €1,200.
Step 4: Apply Age Reduction
The vehicle was first registered in 2022. If importing today, the vehicle is over 3 years old but not more than 4 years, so a 30% age reduction applies to the base VRT only: €3,432 × 30% = €1,030 reduction.
Step 5: Final VRT
The NOx levy adds a significant amount to the total. Without it, the VRT would be just €2,402. This illustrates why diesel vehicles are increasingly expensive to register in Ireland.
Worked Example 2: Imported Car from the UK
Importing a car from the United Kingdom is one of the most common scenarios for Irish VRT. Since Brexit, vehicles from Great Britain are treated as non-EU imports, which adds customs duties and import VAT on top of VRT. However, the VRT calculation itself follows the same formula. Let's work through a realistic example.
Vehicle: 2021 BMW 320d xDrive, 132 g/km CO₂, diesel, purchased at auction in Birmingham for £18,000 (approximately €21,000 at current exchange rates)
Step 1: Determine OMSP
The UK purchase price is not the OMSP. After checking DoneDeal and Carzone for equivalent vehicles, the Irish market OMSP is determined to be €28,000. This higher figure reflects the premium that Irish buyers pay for these vehicles in the domestic market.
Step 2: Identify the Band
CO₂ emissions of 132 g/km fall into Band C (111–140 g/km). The band rate is 15.6%.
Step 3: Calculate Base VRT
€28,000 × 15.6% = €4,368
Step 4: Calculate NOx Levy
This Euro 6 diesel has NOx emissions of 65 mg/km. The NOx levy is approximately €960.
Step 5: Apply Age Reduction
The vehicle was first registered in 2021. It is over 4 years old but not more than 5 years, so a 40% age reduction applies to the base VRT only: €4,368 × 40% = €1,747 reduction.
Step 6: Final VRT
Add to this the customs duties (2.5% of value for cars from Great Britain post-Brexit) and import VAT (23% of the value plus customs duty), and the total landed cost becomes significantly higher than the auction price alone. Always calculate the complete cost before committing to a UK purchase. Use our Import Car VRT Calculator for a full estimate including customs and VAT.
Worked Example 3: Electric Car
Electric vehicles represent the most dramatic VRT savings available in Ireland. Let's calculate the VRT for a fully electric vehicle to see just how significant the savings are compared to equivalent diesel or petrol cars.
Vehicle: 2023 Hyundai Ioniq 5, 0 g/km CO₂, fully electric (BEV), OMSP €32,000
Step 1: Identify the Band
CO₂ emissions of 0 g/km fall into Band A (0–60 g/km). The band rate is 0%.
Step 2: Calculate Base VRT
€32,000 × 0% = €0. No VRT is owed on the base amount because the band rate is zero.
Step 3: NOx Levy
Fully electric vehicles produce zero tailpipe emissions and are completely exempt from the NOx levy. No NOx levy applies.
Step 4: EV Relief
As a Battery Electric Vehicle (BEV), this car qualifies for up to €5,000 in EV VRT relief. However, since the base VRT is already zero, the relief is effectively redundant. It cannot reduce a tax that is already zero. The practical effect is that no VRT is owed at all.
Step 5: Final VRT
Compare this to a diesel SUV of similar value with CO₂ emissions of 185g/km (Band G, 34.6%). That vehicle would owe €11,072 in base VRT plus up to €4,800 in NOx levy — a total of over €15,000. The EV saves more than €15,000 in VRT alone. This is why electric vehicles are the cheapest vehicles to register in Ireland from a tax perspective. Use our Electric Car VRT Calculator to model specific EV scenarios including relief eligibility.
VRT Calculation Formula Summary
Here is the complete VRT formula in one place, with every variable explained. Use this as a quick reference when calculating VRT for any vehicle.
VRT = (OMSP × Band Rate) + NOx Levy − Age Reduction − EV Relief
OMSP = Open Market Selling Price (Irish market value)
Band Rate = Percentage from CO₂ band table (0% to 40.6%)
NOx Levy = Diesel only, based on mg/km NOx output (capped at €4,800)
Age Reduction = 0%–50% of base VRT, based on vehicle age
EV Relief = Up to €5,000 for BEVs, up to €2,500 for PHEVs
Step-by-Step Process
- Determine the OMSP using Irish market data or the Revenue OMSP tool
- Find the CO₂ emissions figure on the Certificate of Conformity
- Match the CO₂ figure to the VRT band table and note the rate
- Multiply OMSP by the band rate to get the base VRT
- Calculate the NOx levy if the vehicle is diesel
- Apply the age reduction factor if the vehicle is over 12 months old
- Deduct EV relief if the vehicle qualifies
- The result is the total VRT you owe Revenue
Key VRT Calculation Terms
- OMSP (Open Market Selling Price)
- The estimated price your vehicle would sell for on the Irish open market. Revenue uses this as the basis for VRT calculation. It is not the price you paid abroad.
- CO₂ Emissions Band
- A classification system based on the vehicle's carbon dioxide output measured in grams per kilometre (g/km). Each band carries a different VRT percentage rate.
- WLTP
- Worldwide Harmonised Light Vehicles Test Procedure. The current EU testing standard for measuring CO₂ and NOx emissions. Replaced NEDC from September 2018.
- NEDC
- New European Driving Cycle. The older emissions testing standard used before September 2018. Vehicles registered before that date may use NEDC figures for VRT.
- NOx Levy
- An additional charge applied to diesel vehicles based on nitrogen oxide emissions in mg/km. Calculated per mg/km above the threshold and capped at €4,800 for passenger cars.
- NCTS (National Car Testing Service)
- The organisation that conducts VRT inspections at centres across Ireland. They verify vehicle details and facilitate the Revenue registration process.
- IRN (Irish Registration Number)
- The registration number assigned to a vehicle when it is registered in Ireland through Revenue. Format is typically a county code followed by numbers and letters.
- Revenue Commissioners
- The Irish tax authority responsible for collecting VRT, setting rates, and managing the vehicle registration system through the National Vehicle and Driver File.
Frequently Asked Questions
1. What is the basic VRT formula in Ireland?
The basic VRT formula is: VRT = (OMSP × Band Rate) + NOx Levy. OMSP is the Open Market Selling Price, the Band Rate depends on the vehicle's CO₂ emissions, and the NOx levy applies only to diesel vehicles. Age reductions and EV reliefs are then applied to reduce the final amount.
2. How do I find the correct CO₂ band for my car?
Check your vehicle's Certificate of Conformity or type approval document for the official CO₂ emissions figure in g/km. Then match that figure to the Revenue VRT band table: Band A is 0–60 g/km, Band B is 61–110 g/km, Band C is 111–140 g/km, and so on up to Band H at 226+ g/km.
3. What is OMSP and how does Revenue calculate it?
OMSP stands for Open Market Selling Price. It is the price at which a vehicle would sell in the Irish open market under normal conditions, including all applicable taxes. Revenue determines OMSP using dealer price lists, online listings from DoneDeal and Carzone, auction data, and their own OMSP tool on ROS.
4. Do all diesel cars pay the NOx levy?
Yes, all diesel-powered vehicles pay the NOx levy when registered in Ireland, regardless of age. The levy is calculated based on the vehicle's NOx emissions in mg/km and is capped at €4,800 for passenger cars. Petrol, hybrid, and fully electric vehicles are exempt.
5. Do electric vehicles pay any VRT at all?
Fully electric vehicles (BEVs) fall into Band A (0% VRT rate) because they produce zero CO₂ emissions. They also qualify for up to €5,000 in EV VRT relief, though this is effectively redundant since the base VRT is already zero. In practice, new BEVs pay no VRT in Ireland.
Related Guides
About the Author
Sarah Murphy is an automotive import specialist with over 10 years of experience helping Irish car importers navigate VRT, customs, and vehicle registration. She has assisted thousands of importers with accurate VRT estimates and has been featured in Irish motoring publications.
Questions? Contact the VRT Calculator team for expert advice on vehicle registration tax in Ireland.