Several UK importers and exporters have reported more customs declarations being rejected in 2026, following changes to how the Customs Declaration Service (CDS) validates submitted information. If a declaration you’ve relied on before is suddenly bouncing back, it’s likely down to stricter checks rather than anything unusual about your goods. Our UK customs declaration support team can help you find out why.
Why Are More Customs Declarations Being Rejected in 2026?
Throughout 2026, HMRC has continued to tighten the Customs Declaration Service, which fully replaced the older CHIEF system. Recent updates have introduced stricter validation of certain data elements, particularly around preference and origin codes, meaning declarations that may previously have been accepted with incomplete or loosely accurate information are now more likely to be rejected outright.
In practical terms, this means fields that were once treated as a formality, such as commodity code detail or valuation information, are now checked more rigorously before a declaration is accepted.
What Changed with the Customs Declaration Service (CDS)?
CDS has been through a series of incremental updates since it became the UK’s mandatory system for customs declarations. More recent changes affecting importers and exporters include how post-clearance amendments are notified and tighter validation rules on the accuracy and completeness of preference and origin data submitted with a declaration.
Because CDS is regularly updated, it’s worth checking the latest guidance on GOV.UK, or asking your customs agent, rather than assuming the process works the same way it did even a few months ago.
Common Reasons Declarations Get Rejected
The most frequent causes of rejection we see include:
- Commodity codes that are incomplete, outdated, or don’t match the goods being declared
- Missing or inconsistent valuation information
- Incorrect or unsupported claims to preferential origin
- EORI or VAT details that don’t match HMRC’s records
- Mismatches between the declaration and supporting documents, such as the commercial invoice or packing list
What Happens When a Declaration Is Rejected?
A rejected declaration needs to be corrected and resubmitted before goods can clear customs, which can delay release at the border. Depending on the nature of the error, this might mean a quick fix, or it could require gathering additional documentation to support the declaration.
Repeated rejections can also slow clearance more broadly, since each resubmission must go through the same validation checks again.
How Can You Reduce the Risk of Rejection?
A few practical steps can reduce how often your declarations get flagged:
- Double-check commodity codes are accurate and specific to the goods being shipped, not just broadly similar
- Make sure valuation and origin information is consistent across your declaration and supporting documents
- Keep EORI and VAT details up to date and correctly linked
- Work with a customs agent who stays current on CDS changes, rather than relying on processes that haven’t been reviewed recently
Which Ports Does This Apply To?
These CDS validation changes apply to declarations regardless of which UK port your goods move through. MartinTrux prepares and reviews declarations for shipments moving via ports including Dover and London Gateway.
Frequently Asked Questions
Has something changed, or am I just making more mistakes?
If declarations that previously went through without issue are now being rejected, it’s more likely down to stricter CDS validation than a sudden change in your own processes.
Can a rejected declaration affect my goods being released?
Yes. Goods generally can’t be released until a corrected declaration has been accepted, so rejections can cause delays at the border.
Should I use a customs agent instead of self-filing?
Many businesses find that working with a customs agent who tracks CDS changes reduces the risk of rejection, particularly as validation rules continue to be updated through 2026.
How MartinTrux Can Help
MartinTrux has prepared and reviewed customs declarations for UK importers and exporters since 1982, with over 500 years of combined team experience across our Dover, Heathrow, and Manchester offices. We are accredited by HMRC as an Authorised Economic Operator (AEO), and we keep our declaration processes up to date as CDS continues to evolve.
This article is intended as general guidance and not formal customs advice, and CDS requirements are subject to ongoing change. If your declarations are being rejected more often than they used to be, get in touch with our team, and we will help you work out why.