Most production incidents in this stack fall into a few families. Knowing the pattern shortens the fix.
GVMS check-in rejection
Almost always a data mismatch. Check vehicle registration, trailer detail, and that every declaration reference bundled into the Goods Movement Reference is present and correct. If one reference is missing, the GMR fails.
CDS declaration hangs
Often a commodity code issue: same code, different formatting, or a value that fails a duty calculation. Read the CDS response codes carefully rather than resubmitting.
ICS2 filing gap
A common failure mode is neither party filing because both assumed the other would. Confirm ICS2 responsibility per lane in writing and audit it. A Northern Ireland customs systems explainer covers the responsibility split.
NCTS unexpected requirement
Comes up when a route through Ireland was not flagged at planning. Once the driver is at the border it is late. Push route checks to the booking stage.
TSS validation errors
TSS validation errors are almost always the friendliest failures in the stack. They stop the entry before it reaches CDS, ICS2, GVMS or NCTS, which is why the input layer is where quality effort belongs.
Practical takeaway
Read the actual error, do not resubmit blindly. Every error names the system that surfaced it.
Want to stop chasing errors after the fact? Watch a demo to see how iCustoms.ai surfaces them at the entry point.
