How to Prepare for a Customs Audit: A Practical Guide for UK Importers & Exporters

Why Customs Audits Matter

HMRC conducts customs audits to ensure businesses are complying with UK customs law. These audits can be routine, risk‑based, or triggered by discrepancies in declarations. A well‑prepared business can pass an audit smoothly — but poor preparation can lead to penalties, duty reclaims, or even suspension of customs authorisations.

This guide gives you a clear, structured approach to preparing for a customs audit and maintaining strong compliance year‑round.

1. Understand What HMRC Looks For

During a customs audit, HMRC typically reviews:

• Import and export declarations
• HS/commodity code accuracy
• Valuation methods
• Origin claims and supporting evidence
• Duty relief usage (IP, OP, RGR, TA, warehousing)
• Supplier documentation
• Internal processes and record‑keeping
• Compliance with authorisation conditions

Knowing what they expect helps you prepare effectively.

2. Keep Accurate and Complete Records

HMRC requires importers and exporters to keep detailed records for at least six years.

Your records should include:

• Commercial invoices
• Packing lists
• Bills of lading / airway bills
• HS code classification notes
• Origin evidence (statements, certificates)
• Duty relief documentation
• CDS declaration copies
• Supplier correspondence
• Internal compliance procedures

Good record‑keeping is the foundation of a successful audit.

3. Review Your HS/Commodity Codes

Incorrect classification is one of the most common audit issues.

Check that:

• Codes match the product description
• Chapter and section notes have been applied
• GRIs have been followed
• Supplier codes have been verified
• Classification decisions are documented

A clear audit trail protects you from penalties.

4. Verify Customs Valuation

HMRC checks whether your customs values are correct and complete.

Ensure you include:

• Product cost
• Freight
• Insurance
• Packing
• Commissions (where applicable)
• Correct exchange rates

Incorrect valuation can lead to duty reclaims and interest charges.

5. Check Your Origin Claims

If you claim preferential duty under trade agreements, HMRC will expect:

• Valid supplier statements of origin
• Evidence of manufacturing processes (if required)
• Proof that rules of origin are met
• Records kept for audit

Incorrect origin claims can result in duty repayment and penalties.

6. Review Duty Relief Usage

If you use reliefs such as IP, OP, RGR, TA, or warehousing, HMRC will check:

• Authorisation conditions
• Re‑export deadlines
• Processing records
• Stock movements
• Correct procedure codes
• Compliance with disposal rules

Reliefs save money — but only when used correctly.

7. Ensure Supplier Documentation Is Accurate

Supplier errors often cause audit issues.

Check that suppliers provide:

• Correct invoices
• Accurate descriptions
• Proper origin statements
• Certificates for controlled goods
• Packing lists that match the shipment

If suppliers are inconsistent, create a documentation template for them.

8. Review Your Internal Processes

HMRC may ask about your internal controls, including:

• Who classifies goods
• How declarations are checked
• How origin is verified
• How duty reliefs are managed
• How records are stored
• How errors are corrected

Clear, documented processes demonstrate strong compliance.

9. Conduct Internal Compliance Checks

Before HMRC arrives, perform your own audit:

• Sample declarations for accuracy
• Check HS codes and valuation
• Review origin claims
• Verify duty relief compliance
• Ensure records are complete
• Identify and correct errors

Proactive checks reduce risk and build confidence.

10. Prepare Your Team

Make sure relevant staff understand:

• Their roles in the audit
• Where records are stored
• How processes work
• How to answer HMRC questions clearly and accurately

A confident, well‑prepared team makes a strong impression.

Common Issues Found in Customs Audits

HMRC frequently identifies:

• Incorrect HS codes
• Under‑declared customs values
• Invalid origin claims
• Missing documentation
• Incorrect procedure codes
• Misuse of duty reliefs
• Poor record‑keeping
• Supplier errors
• Inconsistent internal processes

Most of these issues are preventable with good preparation.

How We Help You Prepare for a Customs Audit

We support businesses with:

• Pre‑audit compliance reviews
• HS code verification
• Origin and valuation checks
• Duty relief compliance assessments
• Record‑keeping audits
• Supplier documentation reviews
• Ongoing customs compliance support

Our goal is simple: help you pass your customs audit with confidence and avoid costly penalties.

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 preparing for a customs audit, our specialists are ready to support you.

Get in touch for expert customs audit preparation and compliance guidance.