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Last reviewed: 6 July 2026
V55/5 form · Box 44
NOx — Nitrogen Oxides (g/km or g/kWh)
What goes in box 44
Box 44 of the DVLA V55/5 form is for nox — nitrogen oxides (g/km or g/kwh).
The nitrogen oxides figure from the Certificate of Conformity. On EU registration certificates it's field V.3. Leave blank if you don't have this information.
What to enter
| Field | Type | Required? |
|---|---|---|
NOx (g/km or g/kWh) The nitrogen oxides figure from the Certificate of Conformity. On EU registration certificates it's field V.3. Leave blank if you don't have this information. | number | Optional |
Source
This page is generated from the same field definitions our V55/5 tool validates against, mapped to the official DVLA guidance.
V355/5 official guidance (GOV.UK)v55-5.com is an independent service and is not affiliated with the DVLA.
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