Paper to eCoC: What a Certificate of Conformity Is and Who It Affects in the UK
So what is a Certificate of Conformity?
A Certificate of Conformity (CoC) is a document a vehicle manufacturer issues to declare that a particular vehicle was built in conformity with an approved type. It holds the key technical data — dimensions, masses, emissions class, type approval number — and is needed before a vehicle can be registered in any UK or EU member state.
CoCs have historically been paper documents. From 5 July 2026, the UK — keeping pace with the EU's timeline — is moving over to electronic Certificates of Conformity, or eCoCs.
And what is an eCoC?
An eCoC is the digital counterpart of a paper CoC. It's a structured XML data file — an Initial Vehicle Information (IVI) file, to be precise — that carries exactly the same regulatory and technical information as the paper version, only in a machine-readable form.
Every eCoC has to be digitally signed to vouch for its authenticity and data integrity, then submitted to the VCA electronically.
Who is caught by the eCoC mandate?
- Category M vehicles — passenger cars, buses and coaches
- Category N vehicles — goods vehicles (N1, N2, N3)
- Category O vehicles — trailers (O3 and O4 included)
- Every series type — full, medium and small series approvals
For now, category L, T, C, R and S vehicles fall outside the eCoC requirements and should carry on using paper CoCs.
Multi-stage builds and vehicle body builders
The eCoC mandate carries particular weight for multi-stage vehicle builds. A great many commercial vehicles are put together in stages — one manufacturer produces the base vehicle (a chassis or chassis-cab), then a body builder or converter finishes it off.
Every stage holding its own type approval has to submit eCoC data. The base vehicle manufacturer files an eCoC for the incomplete vehicle, and the body builder files a separate eCoC for the completed one. Getting this data exchange between stages to line up is one of the bigger challenges of the transition.
How eCoCs differ from paper CoCs
| Aspect | Paper CoC | eCoC |
|---|---|---|
| Format | Printed document | IVI XML file |
| Authentication | Wet signature / stamp | XAdES digital signature |
| Submission | Travels with the vehicle | VCA portal or API |
| Validation | Reviewed by hand | Automated XSD schema check |
| Accessibility | Physical copy only | VIN-based public lookup (Phase 2) |
Where eCoC EU² helps
eCoC EU² software takes care of the whole eCoC lifecycle for UK manufacturers: