What Is a HMRC Customs Audit?
A customs audit is a compliance check conducted by HMRC to verify that a business has been correctly classifying goods, declaring the right customs values, paying the correct duties and VAT, and maintaining proper records. Audits can be triggered by a routine selection, a risk-based referral, or discrepancies identified in your customs declarations. The GOV.UK compliance checks guidance provides an overview of what to expect.
Being selected for an audit doesn’t necessarily mean HMRC suspects wrongdoing — many audits are routine. However, being unprepared can turn a straightforward check into a lengthy and costly investigation.
Types of Customs Audits
Desk-Based Reviews
HMRC may request documents by post or email. You’ll typically receive a letter specifying which records are needed and the time period under review. This is the least invasive form of audit.
On-Site Visits
An HMRC officer visits your premises to inspect records, interview staff, and observe your customs processes. These visits are usually scheduled in advance, giving you time to prepare.
Post-Clearance Audits (PCAs)
These focus specifically on customs declarations already processed. HMRC reviews a sample of entries to check classification, valuation, origin claims, and duty calculations. PCAs can cover up to four years of declarations.
Essential Steps to Prepare
1. Organise Your Records
HMRC requires you to retain customs-related documents for a minimum of six years. Before any audit, ensure you can quickly access:
- Customs declarations (C88/E2 entries)
- Commercial invoices and purchase orders
- Transport documents (bills of lading, airway bills, CMR notes)
- Origin certificates and supplier declarations
- MPIVS statements and C79 certificates
- Correspondence with your customs broker
2. Review Your Commodity Codes
Classification errors are the most common finding in customs audits. Before HMRC asks questions, review your top commodity codes to confirm they are correct. If any have changed due to tariff updates, ensure your declarations reflect the current codes.
3. Verify Valuation Declarations
Check that customs values on recent declarations match your commercial invoices and include all required adjustments (freight, insurance, royalties, assists). Discrepancies between invoice values and declared customs values are a major audit focus.
4. Confirm Origin Claims
If you have claimed preferential duty rates based on origin, make sure you hold valid origin documentation for every claim. Under the UK–EU Trade and Cooperation Agreement, suppliers’ declarations of origin must meet specific requirements — missing or invalid documentation can result in duty being recalculated at the full rate.
5. Check Licence and Permit Compliance
If any of your imports require licences (e.g., dual-use goods, agricultural products), verify that all shipments during the audit period were covered by valid licences and that any reporting conditions were met.
6. Prepare Your Team
Ensure that staff who handle customs matters understand the audit process and can answer questions clearly. Designate a primary point of contact for the HMRC auditor, and brief them on the areas likely to be covered.
During the Audit
- Be cooperative and professional. Respond to information requests promptly and honestly.
- Ask questions. If you’re unsure what HMRC is looking for, ask for clarification.
- Take notes. Document what the auditor requests, what they review, and any preliminary observations they share.
- Don’t volunteer unnecessary information. Answer what is asked, accurately and completely, but avoid offering up areas HMRC hasn’t raised.
After the Audit
HMRC will issue a report outlining their findings. If discrepancies are identified, you may face a duty demand (with interest), a penalty, or a requirement to correct your processes going forward. You have the right to challenge findings if you disagree.
If you’re facing a customs audit or want to conduct a pre-audit self-assessment, contact our customs team for expert support throughout the process.
Need Help With Customs Clearance?
Contact our team. Submit a clearance request online or visit agencjacelna.uk

