The most common mistakes in customs clearance are incorrect classification of goods under an HS code, the importer or exporter lacking a valid EORI number, and discrepancies between the declaration data and the commercial invoice or transport document. Each of these mistakes can result in goods being held for clarification, an additional physical inspection, or the need to correct a CDS declaration after clearance has already taken place. Below we show at which stage of the process mistakes most often occur and how to eliminate them.
Contents
In brief — what you'll learn
- ✓ How to prepare the process and documents
- ✓ How the declaration and check are carried out
- ✓ How to maintain compliance and settlements
How to prepare the process and documents
Division of responsibility between the parties
It's essential to distinguish responsibility between the importer, exporter and customs representative, since this determines the scope of data submitted to official systems. Incorrectly assigning roles results in the need to submit a correction to the declaration or a delay in the release of goods. A signed representation agreement and a clearly defined customs power of attorney form the basis for a safe division of duties between the parties to the transaction.
Minimum data set for the declaration
Every customs declaration requires at least: the CN code of the goods, the customs value confirmed by an invoice, sender and recipient details matching their EORI, the transport document number, and the country of origin. Missing even one of these elements causes the declaration to be held in the CDS or S&S GB system until the declarant provides the missing data.
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How the declaration and check are carried out
Operational stages from pre-notification to release
The most common risk points and how to reduce them
The most common mistakes include: an incorrect CN code resulting in overpaid or underpaid duty, missing permits required for regulated goods, and a mismatch in value between the invoice and the declaration. Introducing a two-stage data check — by the logistics team and by the customs agency — cuts the number of system rejections by more than half.
How to maintain compliance and settlements
Record-keeping, corrections and evidence of due diligence
Customs documents must be kept for at least 4 years in line with HMRC requirements. A correction to a declaration (amendment) must be submitted promptly once an error is found — delaying it increases the risk of an administrative penalty. Complete documentation — invoice, CMR, permits, correspondence with HMRC — serves as evidence of due diligence during any check.
Working with a customs agency and internal audit
Regular internal audits — at least once a quarter — help detect recurring classification or valuation mistakes before HMRC does. A customs agency acting as a direct representative takes on joint liability for the accuracy of the declaration, which is why choosing an accredited partner and having a clear contract scope are key elements of managing customs risk.
Summary
In summary: in the area of 'customs clearance mistakes', what matters most is running the process according to current official guidance, with a clear division of responsibility and documentation of every decision. This approach reduces delays, cuts the number of corrections needed and makes it easier to defend your settlements during a check. If any requirement is unclear, check the current GOV.UK guidance or consult an accredited customs agency.
Legal basis and sources
- HMRC: UK Trade Tariff (UI)
- HMRC: Check a UK EORI Number API
- GOV.UK: Making an entry summary declaration
If the regulations or system announcements are updated, check the current GOV.UK or KAS guidance before submitting a declaration.
Frequently asked questions
What are the most common mistakes in customs clearance between Poland and the United Kingdom?
The most common are: an incorrect CN code for the goods, an understated or overstated customs value, the importer or exporter lacking an EORI number, a mismatch between the invoice and the transport document, and missing permits required for regulated goods. Each of these mistakes can cause a shipment to be held and require a correction to the declaration.
Who is responsible for mistakes in a customs declaration — the importer or the customs agency?
This depends on the type of representation. Under direct representation, the customs agency shares joint liability with the importer for the accuracy of the declaration. Under indirect representation, full liability rests with the agency. The contract should clearly define the scope of the power of attorney and the division of duties, to avoid disputes during an HMRC check.
How long must customs documents be kept in the United Kingdom?
HMRC requires customs documents to be kept for at least 4 years from the date of declaration. This includes commercial invoices, transport documents (CMR, AWB), specifications of goods, confirmations that the declaration was accepted, and any correspondence with the customs authority. These documents provide evidence of due diligence and form the basis of a defence in the event of a check or dispute.
What should I do if an error is discovered after a customs declaration has been submitted?
A correction to the declaration (amendment) should be submitted promptly through the CDS (Customs Declaration Service) system. The sooner the error is reported, the lower the risk of an administrative penalty. If the goods have already been released, HMRC can issue a C18 (Post Clearance Demand Note) requiring payment of the shortfall. The customs agency should be informed as soon as a discrepancy is discovered.
How can delays in customs clearance caused by document mismatches be avoided?
It's essential to carry out a document completeness check before the vehicle is even loaded. Consistency between the commercial invoice, the specification of goods and the transport document should be verified — particularly regarding the description of goods, value, weight and CN codes. A two-stage check by logistics and the customs agency eliminates most causes of border hold-ups.
Related guides
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