The migration of all UK export declarations from CHIEF to the Customs Declaration Service (CDS) is now firmly behind us. The final cutover took place in November 2024 and the system has since processed several full peak seasons. With the migration period over and HMRC's transitional easements gradually withdrawn, this is a useful moment for exporters to review how the new platform actually behaves.
What changed at the cutover
CHIEF, the system that processed UK declarations for thirty years, was retired in two stages. Imports moved to CDS in late 2022; exports followed in November 2024. CDS is built around the Union Customs Code (UCC) data model and uses a structured data set with around 100 fields per declaration, considerably more granular than CHIEF.
Key differences for exporters:
- New data fields including additional procedure codes (APCs) instead of CHIEF's CPCs
- Different valuation methods with method 1 (transaction value) declared explicitly
- Updated DUCR/MUCR rules for consolidations
- New status messages — accepted, under risk, under control, cleared, departed
What HMRC has tightened since the cutover
In the first year after migration, HMRC operated a "soft landing" approach: declarations with minor errors were often allowed to clear with a warning. That period has now ended. HMRC is enforcing data quality more strictly, and we are seeing more declarations held for amendment where previously they would have moved through.
The most common reasons for held declarations are:
- Mismatch between the commodity code and the goods description
- Incorrect or missing nature of transaction code
- Wrong supervising office for special procedures
- Missing or invalid licence references
Practical impact at the ports
For RoRo exports through Dover, Eurotunnel and Holyhead, the GMR will only validate once every linked declaration has a "permission to progress" status. Errors that previously caused only paperwork friction now stop the truck. Hauliers should not arrive at the port without confirmation that every declaration on the GMR has cleared.
For air and deep-sea exports the situation is less time-critical but the same data quality requirements apply.
What exporters should do now
- Reconcile your CHIEF-era procedure codes against the current CDS code list
- Review your declaration templates with whoever files on your behalf
- Make sure your broker is fully on CDS and not relying on legacy mappings
- Subscribe to HMRC's CDS service notices for downtime and code changes
Need help?
PCS Port Clearance Services Ltd has been filing on CDS since the early phases of migration. Our team handles export declarations 24/7 at every UK port and we can review your existing setup for hidden CHIEF-era assumptions. Call +353 1 960 2215 or email customs@pcsl.uk.com to talk to an AEO-licensed broker — see our exports service page for more.