Troubleshooting UK Transit: Why Your GMR Keeps Failing

First, isolate the failure

A GMR failure is not one problem. It is the visible symptom of an upstream gap. Read the port response carefully — the error usually points at the missing reference.

Common causes and fixes

• Export MRN not lodged in CDS before GMR assembly.
• Transit MRN not issued because Phase 5 rejected the payload — often a missing house consignment or a five-digit commodity code where six are required.
• Import declaration not pre-lodged on the EU side.
• EORI mismatch between the guarantee holder and the declared party. Each of these has a documented fix in this transit customs failure points explained breakdown.

The pattern behind repeated failures

Repeated GMR failures are almost always a workflow problem, not a data problem. Committing the GMR before all four gates have closed produces stub records that fail with different error messages depending on which gate is missing.

FAQ

Why does the same trailer sometimes fail and sometimes pass?
Timing. If a transit MRN is issued after the GMR is committed, the GMR is not automatically updated.

Does re-submitting fix a stub GMR?
Only if the underlying gap is closed first. Otherwise it fails again with the same class of error.

Cut GMR failures at source. Watch a demo to see how iCustoms sequences gates.