Car tax CO2 certificate UK — the Certificate of Conformity (COC) is the definitive document proving your vehicle's CO2 emissions and VED classification. Here is why you need it in 2026.
What Is a Certificate of Conformity?
The Certificate of Conformity (COC) is an official document issued by the vehicle manufacturer that confirms the vehicle meets EU type approval requirements. It contains the official CO2 emission figure, fuel type, engine size, and other technical specifications used to determine your VED band.
Why the COC Matters for Road Tax
The CO2 figure on your COC is the definitive emission figure for your vehicle. If your V5C shows a different CO2 figure, the COC is the evidence you use to correct DVLA's records. The COC is also essential when importing a vehicle — it provides the CO2 data needed to calculate UK road tax.
How to Get a Certificate of Conformity
Request a COC from your vehicle's manufacturer. Most manufacturers charge a fee for this service — typically £30-£60. Some offer digital copies via their customer services portal. Provide your vehicle identification number (VIN) and proof of ownership.
COC for Imported Vehicles
For vehicles imported from the EU, the COC provided at first registration in the origin country is accepted by DVLA. For non-EU imports, a COC or equivalent documentation is required to establish the CO2 figure. If no COC is available, a professional inspection at the VCA determines the CO2 classification.
Conclusion
Car tax CO2 certificate UK: the COC is your authoritative CO2 proof. Request from your manufacturer if your V5C figure is wrong. GOV.UK has import documentation guidance.