Post-Clearance Audit: What HMRC Checks and How to Prepare

Customs clearance is not final; it is provisional. HMRC can audit your customs declarations for up to three years after the date of acceptance.

The HMRC Post-Clearance Audit Process

HMRC's post-clearance audit (PCA) follows a structured, staged process from initial notification through to resolution and any appeal.

Stage 1: Audit Notification

HMRC issues a formal notification letter setting out:

• The scope of the audit (e.g. imports, exports, specific regimes)
• The period under review (up to three years)
• The information they expect you to provide

You typically have 30 days to respond and confirm how and when you will supply the requested records.

Stage 2: Information Request

HMRC will request detailed supporting evidence, which may include:

• CDS or CHIEF declaration data and entry records
• Commercial invoices and packing lists
• Contracts, purchase orders and transport documents
• Certificates of origin and preference (e.g. EUR1, statements on origin)
• Valuation workings, transfer pricing documentation and royalty agreements
• Evidence supporting any special procedures or reliefs used

Maintaining complete, well-organised records is critical to responding within the deadline.

Stage 3: Desk Review

HMRC analysts carry out a desk-based review of your data and documents. They typically focus on:

• Classification – correctness of commodity codes and duty rates
• Valuation – inclusion of all dutiable elements and correct valuation method
• Origin – entitlement to preferential rates and proof of origin
• Customs procedure codes (CPCs) – correct use of reliefs, special procedures and end-use

They compare your declarations against risk indicators, internal benchmarks and any known sector risks.

Stage 4: Site Visit

Where HMRC needs deeper assurance, they may conduct a site visit to your premises to:

• Inspect original records and systems
• Review stock, inventory and process flows
• Interview operational, finance and customs compliance staff

They may test a sample of entries in detail and assess the effectiveness of your internal controls.

Stage 5: Findings Letter

Following their review, HMRC issues a findings letter which:

• Summarises the issues identified
• Sets out proposed adjustments and rationale
• Invites your comments and any further evidence

You have an opportunity to challenge inaccuracies, provide additional documentation and explain your position before any formal assessment is raised.

Stage 6: C18 Demand

If HMRC concludes that duty or import VAT has been underpaid, they will issue a C18 Post Clearance Demand Note. This will typically include:

• The duty and import VAT shortfall
• Penalties, often in the range of 15–30% depending on behaviour
• Statutory interest on the underpaid amounts

Timely engagement and evidence can help reduce penalties, especially where you can demonstrate reasonable care and prompt corrective action.

Stage 7: Appeal Rights

You have formal rights of challenge if you disagree with HMRC's decision. Options include:

• Requesting an internal review by HMRC
• Appealing to the First-tier Tribunal (Tax Chamber)

Strict time limits apply, so it is important to act quickly and keep a clear audit trail of your correspondence and evidence.

The Flip Side: C285 Duty Reclaims

The same three-year window can work in your favour. If you identify that you have overpaid customs duty or import VAT, you can:

• Submit a C285 claim to HMRC
• Provide supporting evidence (amended declarations, invoices, origin proofs, valuation corrections)

Successful C285 claims can recover overpayments within the three-year period, improving cash flow and correcting your customs position.

How to Prepare for a Post-Clearance Audit

• Maintain complete, accessible customs and commercial records for at least three years
• Regularly review classification, valuation, origin and CPC usage
• Document your customs procedures and controls
• Train staff involved in customs, finance and logistics
• Proactively identify and correct errors, including using C285 where appropriate

Being prepared reduces disruption, mitigates risk of penalties and helps you make full use of legitimate duty reclaims.