What do I put in V55/5 boxes 36 and 37 CO2 emissions?
Reviewed 2026-07-10
Short answer
Use the CO2 figures from the Certificate of Conformity, IVA or GB conversion certificate where available. Do not invent figures from online adverts or similar vehicles.
Official position
The V355/5 guidance says box 36 is the CO2 figure from the Certificate of Conformity, using the combined NEDC value or equivalent. It says box 37 specific CO2 emissions WLTP should come from the Certificate of Conformity or IVA/GB conversion certificate.
What to do
Check whether your vehicle has a CoC, IVA, GB conversion IVA or other approval evidence with CO2 values.
Use box 36 for the NEDC or equivalent combined figure where applicable.
Use box 37 for the WLTP specific CO2 figure where applicable.
If the vehicle is older or has no CO2 figure, do not guess; explain the missing data and make sure the tax class route is correct.
Common mistakes
- Copying CO2 from a UK model that is not the same specification.
- Putting engine size in the CO2 box.
- Mixing up NEDC and WLTP figures.
Related help
Official sources
Ready to complete the V55/5?
Once the blocker above is resolved, use the guided V55/5 tool to validate the boxes, prepare the PDF and build the posting checklist.
Start your V55/5