How to Calculate VRT in Ireland: A Step-by-Step Guide

You've found a car. You know the make, the model, the year. You might even have the VIN or a screenshot of the ad. Now you need to figure out what VRT you'll pay when you bring it into Ireland. The question is: where do you even start?

I remember sitting down with my first import, a 2017 Skoda Octavia I'd found on a UK site. I had the advert, I had the reg number, and I had absolutely no idea how to turn that into a VRT number. I spent hours reading Revenue PDFs and forum posts, and I still wasn't sure I'd got it right. When you book your VRT inspection, you will visit an NCTS (National Car Testing Service) centre, where they verify your vehicle's details before registration.

This guide is designed to save you that hassle. I'm going to walk you through a complete VRT calculation from start to finish, using a real car as an example. You'll see exactly what documents you need, where to find the numbers, how to estimate the OMSP, how to apply the right band, and how to check your result against Revenue's official assessment.

By the time you finish reading, you'll be able to calculate VRT for any car in about ten minutes. You'll know where the figure comes from, why it might be different from what the seller or a forum thread told you, and what to do if Revenue's assessment doesn't match your estimate. Let's start with the basics of why getting this right matters so much.

Why Getting the Calculation Right Matters

Here's the thing about VRT. It's probably going to be the biggest single cost of importing a car after the purchase price itself. Get it wrong by a few hundred euro and it's annoying. Get it wrong by a few thousand and you've made a bad financial decision.

I've heard from people who budgeted €1,500 for VRT on a car and ended up paying €3,800. That kind of difference can turn a good import deal into a loss. The UK purchase price might look great, but once you add VRT, customs duty, VAT, shipping, and NCT, the total can easily exceed what you'd pay to buy the same car in Ireland.

The good news is that VRT follows a predictable formula. If you know the three key numbers your car's market value, its CO2 emissions, and its NOx emissions you can calculate a very accurate estimate before you commit to buying anything.

Let me give you a quick example of why this matters. Say you're looking at two cars that cost the same to buy in the UK a 2020 petrol Toyota Corolla and a 2020 diesel BMW 1 Series. Both might be listed at around €12,000 across the water. But the Toyota's VRT will be in the region of €1,200 to €1,500, while the BMW's VRT could easily be €2,500 to €3,000 because of higher CO2 and NOx. That's a difference of over €1,000 for cars at the same purchase price. If you don't run the numbers before buying, you could pick the wrong car and pay for it in VRT.

People often assume that the cheaper the car to buy, the less VRT you pay. That's not how it works. VRT is based on the car's market value in Ireland, not the UK purchase price, and on its emissions profile. A cheap, high-emissions diesel can end up costing more in VRT than the purchase price itself. That's a mistake you only make once.

What You'll Need Before You Start

Before you can calculate VRT, you need to gather the right information. Here's what I recommend having ready:

• The car's registration number (UK reg or VIN). This helps you look up the technical specs online if you don't have the paperwork.
• The Certificate of Conformity (CoC). This is the manufacturer's official document that lists the car's technical specifications. It includes the CO2 figure, NOx figure, fuel type, and engine details. If the seller doesn't have it, you can sometimes get it from the manufacturer or a data service.
• The car's mileage and condition. These affect the OMSP, so be honest about them.
• The V5C logbook (UK cars). This proves the car's history and helps verify the details.
• Photos of the car. Good ones showing any damage, wear, or optional extras. Revenue may ask for these during the VRT assessment process.

If you're buying from a dealer, they should be able to provide the CoC or at least the emissions data. If you're buying privately, you might need to ask the seller to look it up. Don't buy a car without knowing its CO2 and NOx figures, because those two numbers directly determine your VRT rate.

Step 1: Finding Your Car's CO2 and NOx Figures

This is the first thing you need to pin down. The CO2 figure determines which VRT band applies, and the NOx figure determines the NOx levy charge.

Where to Find the CO2 Figure

The official source is the Certificate of Conformity. Every car sold in the EU or UK after 2001 has one. It's a multi-page document with all the technical specs. Look for section 47 (CO2 emissions) or section 49 (fuel consumption and emissions).

If you're buying from a UK dealer, ask them to send you a photo of the CoC emissions page before you commit. Most dealers will do this if you explain you need it for VRT. If they can't or won't, that's a red flag.

If you don't have the CoC, you can look up the CO2 figure using the car's registration number on sites like the UK Government's vehicle enquiry tool or the Dutch RDW site. These databases pull from official records, so they're usually reliable.

Here's the important part. Check whether the CO2 figure is WLTP or NEDC. If the car was first registered after September 2018, it will have a WLTP figure. If it's older, it might have an NEDC figure instead. Revenue will convert NEDC figures to WLTP equivalents before applying the VRT bands, so don't assume the NEDC number is what will be used.

Where to Find the NOx Figure

The NOx figure is on the Certificate of Conformity too, usually in section 26 or section 47. It's measured in milligrams per kilometre (mg/km). Not all CoCs show the NOx figure in a clear way. Sometimes it's buried in the technical data under a heading like "pollutant emissions."

If you can't find the NOx figure on the CoC, check the UK Government's vehicle enquiry tool again. Some entries include NOx data. For newer cars (post-2019), the NOx figure is almost always available because WLTP certification requires it.

For older cars, you might not find a NOx figure anywhere. In that case, Revenue may use a default value. This is usually higher than the actual figure, so try to get the real number if you can.

What If You Can't Find Either Figure?

If you're struggling to find the emissions data, here are some backup options:

• Contact the manufacturer with the VIN and ask for the CoC data sheet.
• Use a paid data service like Car Analytics or HPI Check. They often include emissions data.
• Check the car's advertisement. UK dealers are required to show CO2 figures for most cars. It might be in the small print or a separate tab.

Step 2: Estimating the OMSP

This is the trickiest part of the calculation, because Revenue's OMSP isn't published upfront. You have to estimate it yourself based on the Irish market.

Revenue's Method for Determining OMSP

Revenue builds its OMSP database from several sources. They look at actual sales data, dealer listings on Irish websites, trade price guides like Glass's Guide and CAP, and the details you provide when registering the car. For a typical passenger car, the OMSP is supposed to represent what the car would sell for in a normal arms-length transaction on the Irish market.

Revenue considers the following factors when setting the OMSP:

• Make, model, and year of first registration
• Engine type, size, and fuel type
• Transmission (manual or automatic)
• Trim level and optional extras
• Mileage
• General condition (damage, wear, service history)
• Previous Irish registrations (if any)

How to Estimate OMSP Yourself

The simplest way is to search DoneDeal.ie for similar cars. Look for the exact same model, year, engine, and as close a trim level as possible. Note down the prices of at least five similar cars, and take the average. That's your starting point.

Be realistic about the condition. If the car you're importing has higher mileage or visible damage, adjust the estimate downward. Revenue will do the same.

Also consider the NI or UK market difference. Sometimes cars are cheaper in the UK because of market conditions. Revenue's OMSP is based on the Irish market, not the UK one. So a car that's cheap in Birmingham might still have a high OMSP in Dublin.

Here's a real example. In 2024, I helped someone estimate the OMSP for a 2019 Ford Focus 1.0 EcoBoost. The UK purchase price was £9,500 (about €11,000). But similar cars on DoneDeal were listed between €14,000 and €16,000. We used €15,000 as the OMSP estimate. The actual Revenue assessment came in at €15,200. Close enough.

Step 3: Applying the CO2 Band

Now you have the OMSP estimate and the CO2 figure. Time to apply the band.

The Two Main Bands (WLTP)

• 0 to 120 g/km: 8% of OMSP (minimum €160)
• Over 120 g/km: 13.3% of OMSP (minimum €266)

Check your CO2 figure against these thresholds. If it's under 120 g/km, you're in the lower band. If it's 120 or over, you're in the higher band.

Let's use our example car, a 2019 Ford Focus 1.0 EcoBoost, with a WLTP CO2 of 114 g/km and an estimated OMSP of €15,000.

114 g/km is under 120, so the rate is 8%.

CO2 component: 8% of €15,000 = €1,200

The minimum for this band is €160. Since €1,200 is well above that, we use €1,200.

What If Your Car Uses an Older NEDC Figure?

If your car only has an NEDC CO2 figure, you need to estimate the WLTP equivalent. Revenue uses a conversion formula that generally adds about 15 to 25 g/km to the NEDC figure. The exact formula depends on the car type and fuel, but as a rough guide:

• For petrol cars: add roughly 15 g/km to the NEDC figure
• For diesel cars: add roughly 20 g/km to the NEDC figure

This is not exact. The actual conversion uses a tool called CO2MPAS, which calculates the WLTP equivalent based on specific vehicle parameters. But for estimation purposes, adding 15 to 25 g/km gives you a reasonable ballpark.

Step 4: Calculating the NOx Levy

Now for the NOx levy. Take your car's NOx figure in mg/km and apply the banded rates:

Caps: €4,850 for diesel, €600 for petrol and other.

Our Ford Focus example is a 1.0 EcoBoost petrol. The NOx figure is around 25 mg/km. So the NOx levy is:

25 mg at €5 each = €125

The petrol cap is €600, so this is well within limits.

Total NOx levy: €125

Step 5: Adding It All Up

Now we have both components for our Ford Focus example:

• OMSP: €15,000
• CO2 figure: 114 g/km WLTP
• CO2 component: €1,200
• NOx figure: 25 mg/km
• NOx levy: €125

Estimated VRT: €1,200 + €125 = €1,325

Checking for Reliefs

Our Ford Focus doesn't qualify for any reliefs. It's not electric, not a plug-in hybrid, and not a historic vehicle. But if you're calculating VRT for an electric or plug-in hybrid car, you'd subtract the relief at this point.

For a 2022 Tesla Model 3, for example:

• OMSP: €35,000
• CO2: 0 g/km means minimum €160 CO2 component
• NOx: 0 mg/km means €0 levy
• Gross VRT: €160
• EV relief (up to €5,000 depending on scheme): potentially reduces VRT to €0

That's a dramatic difference and shows why electric cars are so popular with importers.

Step 6: Verifying Your Calculation Against Revenue's Assessment

Once you submit the VRT return and Revenue assesses the car, you'll get their official figure. This is where you can see how close your estimate was.

If Revenue's figure is close to yours within about 10% you did a good job estimating. If it's notably higher, here's what might have happened:

• Revenue used a higher OMSP. This is the most common reason for a difference. Their database might have the car valued higher than your estimate. Check their OMSP against your DoneDeal research.
• Revenue converted the CO2 figure differently. If you used the NEDC figure and they used the WLTP equivalent, the number will differ. Ask to see the conversion calculation.
• The NOx figure was different from what you expected. Sometimes the CoC shows a different NOx value than what Revenue's system uses. Compare the numbers.
• A relief was applied or not applied. Revenue might have applied a relief you didn't know about, or might have denied one you expected.

If Revenue's figure is lower than yours, congratulations. Your estimate was conservative and you've got a pleasant surprise.

Full Worked Example: 2020 Kia Sportage

Let's run through a complete example from start to finish with a different car to make sure the process is clear.

Vehicle: 2020 Kia Sportage 1.6 CRDi Diesel

UK purchase price: £11,500 (approximately €13,350)

Mileage: 42,000 miles

Documents obtained: V5C logbook, Certificate of Conformity, photos of the car

Step 1: Find the CO2 and NOx figures

From the CoC:

• WLTP CO2: 144 g/km
• NOx: 55 mg/km

Step 2: Estimate the OMSP

Searched DoneDeal for 2020 Kia Sportage diesel with similar mileage. Found five listings ranging from €17,500 to €20,000. Average around €18,800. Adjust slightly because our car has average rather than excellent condition.

Estimated OMSP: €18,500

Step 3: Apply the CO2 band

144 g/km is over 120, so the rate is 13.3%.

13.3% of €18,500 = €2,460.50

The minimum for this band is €266, so we use €2,460.50.

CO2 component: €2,460.50

Step 4: Calculate the NOx levy

55 mg/km diesel. First 40 mg at €5 = €200. Next 15 mg at €15 = €225.

Total NOx levy = €425. Diesel cap is €4,850, so no issue.

NOx levy: €425

Step 5: Add them up

Estimated VRT: €2,460.50 + €425 = €2,885.50

If the Revenue assessment came in at around €2,900 to €3,100, you'd know your estimate was solid. If it came in at €3,500, you'd want to check the OMSP Revenue used.

What Happens When You Submit Your VRT Return

Understanding the VRT submission process helps you check your calculation against reality. Here's what happens after you buy the car and bring it into Ireland.

You submit a VRT return through Revenue's online system (ROS) or in person at a VRT office. You provide the car's details: make, model, year, VIN, mileage, CO2, NOx, fuel type, and your estimated value. Revenue then runs this through their system and produces the official assessment.

The assessment comes back with:

• The OMSP Revenue has assigned
• The CO2 figure they used and the band applied
• The NOx figure and levy calculated
• The total VRT due

This is the moment of truth. You compare it to your estimate. If the numbers are close, great. If not, you now know where the difference came from. Was it the OMSP? The CO2 band? The NOx levy?

The key thing to check is the breakdown. Revenue will show you the OMSP but they might not explain how they got there. If the OMSP seems high, ask for the comparables they used. You have a right to understand how the figure was reached, even though Revenue doesn't always volunteer this information.

If the CO2 or NOx figures don't match what's on your Certificate of Conformity, point this out. A simple data entry error can cost you hundreds of euro.

Common Pitfalls in the Step-by-Step Process

After helping several people through this process, here are the pitfalls I see most often.

Pitfall 1: Using the wrong CO2 figure. You look up the car online and it says 110 g/km. But that's the NEDC figure, not the WLTP. Revenue converts it and the actual WLTP figure is 126 g/km. Suddenly you're in the higher band. Always confirm whether your CO2 figure is WLTP or NEDC.

Pitfall 2: Guessing the NOx figure. Some online databases don't show NOx at all. People assume it's low and skip the check. Then they get an assessment with a default NOx figure that's higher than expected. Get the real figure from the CoC.

Pitfall 3: Overestimating the OMSP. Actually, this is the opposite of most problems. Some people assume the OMSP will be low because the UK price was low. Then Revenue hits them with a higher number. Always be conservative in your estimate.

Pitfall 4: Forgetting about minimum VRT. Even very old or low-value cars pay a minimum. The minimum for the lower band is €160, for the higher band it's €266. Plus the NOx levy on top. There's no scenario where VRT is zero for a standard Category A car.

Pitfall 5: Not allowing for exchange rates. If you're buying in pounds sterling, the EUR/GBP rate affects your total cost but not the VRT calculation directly. However, if you used an online VRT calculator that converted the UK price to euro, and the exchange rate has changed, your estimate could be off.

What About Cars Already Registered in Ireland?

Everything above applies to cars being imported for the first time. But what if you're buying an Irish-registered car that already has VRT paid?

In that case, you don't need to calculate VRT at all. VRT is a one-time tax paid when a vehicle is first registered in Ireland. If the car is already on Irish plates, the VRT has been paid. You just need to make sure the seller has proof of payment, usually through the Vehicle Registration Certificate (VRC).

The one exception is if the car was imported and VRT was never paid properly. This is rare but it happens. If you're buying a recently imported car from a private seller, ask to see the VRC. If they can't produce it, be careful.

Common Questions About the Step-by-Step Process

How accurate is my estimate likely to be?

If you have the correct CO2 and NOx figures and a realistic OMSP estimate, you should be within 10 to 15% of Revenue's final figure. The biggest variable is always the OMSP.

What if I don't have the Certificate of Conformity?

You can sometimes get a replacement from the manufacturer using the VIN. Some manufacturers charge for this. Alternatively, use online data lookups with the UK reg or VIN.

Can Revenue change the CO2 or NOx figures?

Revenue uses the figures from the Certificate of Conformity or their own database. If the CoC and their database disagree, the issue is usually the NEDC to WLTP conversion.

Do I pay VRT on the car's purchase price?

No. VRT is based on the OMSP, which is Revenue's assessment of the Irish market value. The purchase price and any shipping costs are separate.

Should I pay someone to do the VRT calculation for me?

If the numbers are straightforward, you can easily do it yourself. But if the car is unusual, very new, or from a non-EU country, a VRT agent might save you money by getting the OMSP right and handling the paperwork.

Sources: Revenue.ie (VRT manuals, valuation guidelines), Certificate of Conformity data standards, DoneDeal.ie market analysis.