Importer Mistakes: The Most Common Errors and How to Avoid Them

Why Importer Mistakes Matter

Importing goods into the UK involves multiple steps, strict compliance rules, and detailed documentation. Even small mistakes can lead to delays, unexpected duty charges, port storage fees, or HMRC interventions. Many of these issues are avoidable with the right knowledge and preparation.

This guide highlights the most common importer mistakes — and how to prevent them — so your goods move smoothly and compliantly through UK borders.

1. Using the Wrong HS/Commodity Code

Incorrect classification is one of the biggest causes of customs delays and overpaid duty.

Common issues include:

• Copying supplier codes without checking
• Choosing codes based on duty rate rather than product description
• Misclassifying multi‑component or mixed‑material goods
• Ignoring chapter and section notes

Impact:
Incorrect duty/VAT, customs queries, penalties, or seizure of goods.

How to avoid it:
Use the UK Trade Tariff, apply the GRIs, and verify codes with a customs specialist.

2. Incorrect or Incomplete Supplier Documentation

Many delays start with the supplier. Common problems include:

• Missing commercial invoices
• Incorrect values or currency
• Inaccurate product descriptions
• Missing packing lists
• Incorrect origin statements
• Missing certificates for controlled goods

Impact:
Delays, rejections, or additional checks at the port.

How to avoid it:
Provide suppliers with a clear documentation template and check everything before shipping.

3. Misunderstanding Incoterms

Incoterms define who is responsible for customs, transport, duty, and risk. Common mistakes include:

• Assuming the supplier handles customs when they don’t
• Choosing DDP without understanding the implications
• Using EXW when the supplier is not prepared
• Misalignment between buyer and seller responsibilities

Impact:
Unexpected costs, delays, and disputes.

How to avoid it:
Choose Incoterms carefully and ensure both parties understand their obligations.

4. Incorrect Customs Values

Customs value must include:

• Product cost
• Freight
• Insurance
• Packing
• Certain commissions

Common mistakes include:

• Declaring only the product cost
• Using incorrect exchange rates
• Missing freight charges

Impact:
Incorrect duty/VAT, HMRC audits, or penalties.

How to avoid it:
Follow HMRC valuation rules and ensure invoices reflect the full customs value.

5. Not Preparing for Port Requirements

Each port has its own systems and processes. Mistakes include:

• Missing VBS bookings
• Incorrect container numbers
• Hauliers arriving without MRNs
• Not understanding terminal procedures

Impact:
Haulier delays, wasted trips, storage charges.

How to avoid it:
Know the port’s requirements and communicate clearly with your haulier.

6. Missing or Incorrect Transit (T1) Documents

Transit errors are common, especially for EU‑bound goods.

Typical mistakes:

• T1 not created in time
• Incorrect office of departure
• Missing LRN
• T1 not discharged at destination

Impact:
Goods held at the port, fines, or customs investigations.

How to avoid it:
Work with a reliable transit provider and ensure hauliers understand the process.

7. Not Checking Duty Relief Eligibility

Many importers overpay duty because they don’t know reliefs exist.

Commonly missed schemes:

• Inward Processing (IP)
• Outward Processing (OP)
• Returned Goods Relief (RGR)
• Temporary Admission (TA)
• Customs Warehousing

Impact:
Unnecessary duty costs.

How to avoid it:
Review relief options before importing and apply for authorisations where needed.

8. Poor Communication With Hauliers

Hauliers often arrive at ports without the correct information.

Common issues:

• Missing MRN
• Wrong terminal
• Incorrect container references
• No release instructions

Impact:
Delays, wasted time, and extra charges.

How to avoid it:
Send hauliers a clear, complete instruction pack for every shipment.

9. Not Keeping Proper Records

HMRC requires importers to keep detailed records for audits.

Common mistakes:

• Missing invoices
• No origin evidence
• No classification notes
• No proof of duty relief compliance

Impact:
Penalties, duty reclaims, or compliance issues.

How to avoid it:
Maintain organised digital records for every shipment.

10. Relying on Assumptions Instead of Guidance

Many importers assume:

• “The supplier knows what they’re doing”
• “The haulier will sort it out”
• “The code on the invoice must be correct”
• “We’ve always done it this way”

Impact:
Costly mistakes and compliance risks.

How to avoid it:
Verify everything — classification, documents, origin, and port requirements.

How We Help You Avoid Importing Mistakes

We support businesses with:

• HS code classification
• Import declarations
• Supplier document checks
• Duty relief advice
• Transit (T1) documents
• Port‑specific guidance
• Compliance reviews
• Ongoing customs support

Our goal is simple: smooth, compliant, cost‑effective importing with no surprises.

Explore More in Our Knowledge Hub

You can also read:

• Importer Checklists
• HS Code Guides
• Duty Relief Guides
• Port Guides
• Customs Glossary

If you want help avoiding costly importing mistakes, our customs specialists are ready to support you.

Get in touch for expert customs advice and compliance guidance.