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
- The most common mistakes: a wrong commodity code, an invoice value that differs from the declaration, a missing EORI, unclear roles of the parties and missing permits for regulated goods.
- Data on the invoice, specification and transport document must match before you file.
- Correct an error promptly after filing; keep records for 4 years (VAT records for at least 6).
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, among other things: the commodity code (in the UK from the UK Trade Tariff, in the EU the CN/TARIC code), the customs value confirmed by an invoice, sender and recipient details matching their EORI, the transport document number, and the country of origin. Gaps in these data lead to the declaration being rejected or held until the declarant supplies the missing information. The safety and security declaration (ENS) for the UK is filed separately in S&S GB — see what an ENS is and when it is required. Matching the invoice to the declaration is also covered in commercial invoice to the UK — 8 mistakes.
See our full range of UK customs clearance services.
How the declaration and check are carried out
Operational stages from pre-notification to release
- Preparing the data — commodity code, value, the parties' EORI numbers, country of origin, transport documents and any permits.
- Safety and security declaration before the goods arrive: an ENS in S&S GB for the UK (at least 2 hours before arrival for RoRo, at least 1 hour for Eurotunnel) or ICS2 for the EU.
- Customs declaration — import into the UK in CDS; in the EU in the national system (in Poland via PUESC).
- Check — documentary or physical, if the authority orders one.
- Release of the goods and, if an error is found, a correction of the declaration and any payment of the shortfall.
The most common risk points and how to reduce them
The most common mistakes include: an incorrect commodity code resulting in overpaid or underpaid duty, missing permits required for regulated goods, and a mismatch in value between the invoice and the declaration. A two-stage data check — by the logistics team and by the customs agency — helps catch these discrepancies before the declaration is submitted.
How to maintain compliance and settlements
Record-keeping, corrections and evidence of due diligence
According to HMRC, customs declarations and proof of origin must be kept for 4 years (10 years if there is a criminal investigation), and VAT records — including part of the commercial and transport documents — for at least 6 years (source: GOV.UK). A correction to a declaration (amendment) should be submitted promptly once an error is found — delaying it increases the risk of a penalty; see can you correct a declaration after filing and what to do about an error in a customs declaration. 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
Periodic internal checks help detect recurring classification or valuation mistakes before HMRC does. The agency's liability depends on the type of representation: a direct representative makes the declaration in the importer's name and generally is not held jointly liable, while the importer always remains responsible for due diligence — see direct and indirect customs representatives (source: GOV.UK). That is why choosing a customs agency registered with CDS and having a clear contract scope are key elements of managing customs risk.
Summary
Most mistakes can be avoided by checking that the invoice, specification and transport document match before filing, and by settling the roles of the parties clearly. If a requirement is unclear, check the GOV.UK guidance or get in touch — we are a customs agency registered with CDS, UK EORI number.
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 commodity code, 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 agency makes the declaration in the importer's name; the importer is the declarant and is liable for the duties, and according to GOV.UK a direct representative is generally not held jointly liable. Under indirect representation, the agency acts in its own name on the importer's behalf and is jointly liable with the importer. In both cases the importer remains responsible for due diligence. 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?
According to HMRC (GOV.UK 'Archiving your trade documents'), records of goods declared to HMRC — customs declarations and proof of origin — must be kept for 4 years (10 years if there is a criminal investigation), and VAT records for at least 6 years. It is also sensible to keep declaration acceptance confirmations and correspondence with the customs authority. These documents provide evidence of due diligence 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 commodity codes. A two-stage check by logistics and the customs agency eliminates most causes of border hold-ups.
Related guides
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