From Paper to eCoC: What Is a Certificate of Conformity and Who Does It Affect in the UK?
What is a Certificate of Conformity?
A Certificate of Conformity (CoC) is a document issued by a vehicle manufacturer declaring that an individual vehicle has been produced in conformity with an approved type. It contains essential technical data — dimensions, masses, emissions class, type approval number — and is required for a vehicle to be registered in any UK or EU member state.
Until now, CoCs have been paper documents. From 5 July 2026, the UK (following the same timeline as the EU) is transitioning to electronic Certificates of Conformity — eCoCs.
What is an eCoC?
An eCoC is the digital equivalent of a paper CoC. It is a structured XML data file — specifically an Initial Vehicle Information (IVI) file — that contains all the same regulatory and technical information as the paper document but in a machine-readable format.
Each eCoC must be digitally signed to guarantee authenticity and data integrity, and submitted electronically to the VCA.
Who does the eCoC mandate affect?
- Category M vehicles — passenger cars, buses and coaches
- Category N vehicles — goods vehicles (N1, N2, N3)
- Category O vehicles — trailers (including O3 and O4)
- All series types: full, medium and small series approvals
Category L, T, C, R and S vehicles are not subject to eCoC requirements at this time and should continue to use paper CoCs.
Multi-stage builds and body builders
The eCoC mandate is particularly significant for multi-stage vehicle builds. Many commercial vehicles are constructed in stages — a base vehicle (chassis or chassis-cab) is produced by one manufacturer, and a body builder or converter then completes the vehicle.
Each stage that holds its own type approval will need to submit eCoC data. The base vehicle manufacturer submits an eCoC for the incomplete vehicle, and the body builder submits a separate eCoC for the completed vehicle. Coordinating this data exchange between stages is one of the key challenges of the transition.
Key differences from paper CoCs
| Aspect | Paper CoC | eCoC |
|---|---|---|
| Format | Printed document | IVI XML file |
| Authentication | Wet signature / stamp | XAdES digital signature |
| Submission | Accompanies vehicle | VCA portal or API |
| Validation | Manual review | Automated XSD schema check |
| Accessibility | Physical copy only | VIN-based public lookup (Phase 2) |
How COCDesk helps
COCDesk handles the entire eCoC lifecycle for UK manufacturers:
Ready to meet the UK eCoC deadline?
Book a free demo and see how COCDesk can have your eCoC process production-ready before the VCA mandate takes effect.