Our Methodology

How we source, verify, and update every rate on this site — and what to do if something looks wrong.

Our Standard

Every formula, rate, and band on VRT Calculator Ireland traces back to an official government source — Revenue.ie, gov.ie, or gov.uk. We don't estimate or invent tax figures. Where a source isn't directly machine-readable, we cross-corroborate across multiple independent references and note that explicitly on the relevant calculator page, rather than presenting an unverified figure as authoritative.

See our full step-by-step VRT calculation guide for the formulas themselves, or read on for where each figure comes from.

Where Each Figure Comes From

VRT rates & CO₂ bands

Sourced from Revenue's published VRT rate tables for Category A (cars) and Category B (vans), including the WLTP CO₂ band structure and NEDC-to-WLTP conversion formulas.

NOx levy

The tiered mg/km rate structure (€5/€15/€25 per tier) and the €600 (petrol) / €4,850 (diesel) caps are taken directly from Revenue's NOx levy guidance, introduced in 2020.

Motor Tax

Engine-cc, NEDC CO₂, and WLTP CO₂ band tables. Where the official gov.ie/motortax.ie pages weren't directly machine-readable, figures were cross-corroborated across multiple independent sources and verified for internal consistency before publishing — see the note on our Motor Tax Calculator page.

Benefit-in-Kind (BIK)

Sourced directly from Revenue's own Tax and Duty Manual (Part 05-01-01b), including the 2026 Category A1 electric vehicle rates and OMV temporary reduction schedule. Our calculation was verified against two of Revenue's own worked examples before publishing.

UK Vehicle Excise Duty (VED)

Sourced from gov.uk's official vehicle tax rate tables, used only for the UK-side comparison in our UK vs Ireland Car Tax Calculator.

Expected Variance

Our figures are estimates. Revenue's final OMSP valuation for your specific vehicle — which accounts for exact trim, condition, mileage, and market comparables at the time of registration — can differ from our estimate by roughly ±5-10%. Always confirm the exact amount with Revenue or at your NCTS appointment before making purchase decisions.

Spotted an Error?

If a rate looks out of date or incorrect, please contact us — we review and correct figures against the official source as quickly as possible.

Frequently Asked Questions

Are your VRT calculations exactly what I'll pay at the NCTS?

No — treat every figure as an estimate. Revenue makes the final determination of your vehicle's OMSP (Open Market Selling Price) at your NCTS appointment, and that valuation can differ from our estimate by roughly ±5-10%. Use our figures for budgeting and comparison, not as a final quote.

Do you fabricate or estimate any tax rates?

No. Every rate, band, and formula on this site is sourced from an official government publication (Revenue.ie, gov.ie, gov.uk) or, where a page isn't directly machine-readable, cross-corroborated across multiple independent sources before publishing — never invented or guessed.

How often are your rates updated?

We review rates whenever Budget announcements or Finance Act changes are published, and note the effective date on each calculator page. If you spot a figure that looks out of date, use our Contact page to flag it.

Are you affiliated with Revenue or the Irish government?

No. VRT Calculator Ireland is an independent, privately run tool. We are not affiliated with, endorsed by, or operated by Revenue, the Revenue Commissioners, the NCTS, or any government body.