Overview

Making Tax Digital (MTD) has changed how HMRC expects businesses to keep and present records for tax compliance. Whether you are already submitting VAT returns under MTD for VAT or preparing for the roll‑out of MTD for Income Tax, HMRC’s audit and enquiry processes increasingly assume that core business records are digitised and that a clear digital audit trail exists.

This article explains what HMRC expects, how to prepare for an MTD audit, and the best operational and technical practices to reduce audit risk and speed up resolution if HMRC opens an enquiry. The guidance is aimed at business owners, finance teams, and accountants — with practical checklists and sample processes you can adopt immediately.

Contents

1. HMRC Expectations under MTD

HMRC’s Making Tax Digital initiative shifts the focus from paper-based records to digital bookkeeping and online submissions. An audit under the MTD regime expects:

• Digitally maintained source records: sales invoices, purchase invoices, credit notes, receipts and VAT records kept in or exported from functional compatible software.
• MTD-compatible submissions: VAT returns (for businesses already in MTD for VAT) made via compatible software or APIs.
• Retention of an audit trail: an unbroken electronic trail from underlying transactions to the submitted return or declaration.
• Traceable reconciliations: bank reconciliations and nominal ledger adjustments with notes and explanations preserved digitally.
• User and change logs: records showing who changed or uploaded data and when, to help HMRC establish data integrity.

HMRC expects consistency, accuracy and the ability to extract records in readable formats. Where bridging tools, spreadsheets or multiple systems are used, HMRC will ask for proof that data is reliable and the bridging method does not alter source evidence.

2. What HMRC Can Ask For in an Audit or Enquiry

In an MTD-related audit or enquiry, HMRC may request the following items. Preparing these in advance saves time and reduces stress.

• Original sales and purchase invoices (digital copies acceptable where digitised at the point of receipt).
• Bank statements matching to ledger entries and reconciliations for the period under review.
• Exported ledgers and journal histories from your bookkeeping software, showing timestamped entries.
• VAT returns and submissions together with the submission receipts and confirmation of the software used.
• User access and change logs detailing who posted journals, made edits, or imported data.
• Backups and archives that prove continuous retention of records (usually for up to six years — verify current HMRC guidance).
• Contracts, timesheets and CIS records for construction businesses or sectors where PAYE/CIS is relevant.
• Explanations for unusual transactions and documentary evidence for reconciliations or adjustments.

HMRC can request specific extracts from software via powers to inspect records, and, in some formal enquiries, they may require your software to be made available for inspection. Always respond within deadlines and consult your accountant or adviser before submitting additional commentary.

3. Preparing Your Records — Step by Step

Follow this practical, phased approach to ensure MTD audit readiness.

Phase 1 — Assessment and Mapping

1. Identify the reporting scope: Confirm which taxes you submit under MTD (VAT, and potentially Income Tax/ITSA). Map the periods HMRC could review and prioritise the highest risk periods (e.g., where there were large adjustments, refunds or anomalies).
2. Inventory your systems: List all software, spreadsheets and paper records used in the accounting process. Note which are MTD-compatible and where bridging occurs.
3. Data flow mapping: Document how a sales invoice moves from creation to ledger entry, bank reconciliation and tax return. Highlight manual steps and potential risk points where data could be changed or lost.

Phase 2 — Clean-Up and Reconciliation

1. Reconcile ledgers to bank statements: Resolve unexplained reconciling items and create notes for any legitimate timing differences.
2. Clear suspense accounts: Investigate and document entries in suspense or clearing accounts. Long-standing balances attract HMRC attention.
3. Verify VAT codes and rates: Ensure VAT treatment is consistent and justified with supporting invoices and exemptions clearly documented.

Phase 3 — Document and Pack Evidence

1. Export period packs: For each reporting period, export trial balance, sales and purchase ledgers, VAT returns, journal logs and bank reconciliations into a labelled folder.
2. Attach supporting documents: Link or include scanned invoices, receipts, contracts and payroll records referenced to ledger lines. Use file naming conventions that mirror ledger references.
3. Ensure readability: Exports should be in a commonly accepted format (PDF, CSV, or readable reports from your software). Avoid password-protected files unless instructed by HMRC for secure transmission.

Phase 4 — Policies, Rights and Roles

• Define responsibilities: Document who prepares returns, who signs off reconciliations and who has authority to make corrections.
• Access management: Ensure user accounts are current, remove ex-staff access, and maintain a log of privileged users.
• Disaster recovery: Confirm backups are taken regularly and test restores periodically to prove records can be reconstructed.

4. Systems, Software and Integrations

HMRC requires that digital records are kept using functional compatible software (or formats that can be integrated). Choose systems that reduce manual handling while preserving evidence.

Selecting Software

• MTD compatibility: Use software listed as MTD-compatible or with API connectivity for submissions. Confirm the vendor supports extracting audit reports and journals.
• Audit trail capability: Prefer systems that keep immutable change logs and present who made a change, when and why.
• Integration and bank feeds: Automatic bank feeds reduce manual entry errors; ensure bank statements are matched and stored.

Handling Spreadsheets and Bridging

Many businesses use spreadsheets alongside accounting packages. If you do:

• Keep spreadsheets read-only once used for reporting, or maintain a clear version history with timestamps.
• Document how data is transferred between spreadsheets and accounting systems (manual import, CSV export, copy/paste) and retain original exports with timestamps.
• Where bridging software is used to meet MTD filing requirements, maintain documentation proving the integrity of mapping rules and transformations.

Third-party Integrations

If you use third-party apps (POS, ePOS, CRM, payroll, CIS portals), ensure:

• Data flows into your primary accounting system with a documented mapping.
• Source reports from these apps can be exported on demand.
• There’s a documented reconciliation between the third-party reports and your ledger totals.

5. Best Practices for Audit Readiness

Adopt these routines and controls to demonstrate compliance and reduce HMRC scrutiny.

• Regular reconciliations: Monthly bank and VAT reconciliations reduce surprises and evidence good control.
• Documented rationales: Annotate significant or unusual journals with reasons and attach supporting documents.
• Maintain a digital archive: Keep at least the minimum period required by HMRC (commonly six years for most records) and maintain easy retrieval mechanisms.
• Track user activity: Turn on activity logging in software and preserve logs as part of your audit pack.
• Use consistent naming conventions: File names that incorporate dates and reference numbers speed up retrieval during an enquiry.
• Version control for spreadsheets: Use cloud drives with version history turned on and lock down historic reporting files.
• Prepare a narrative: For each reporting period keep a short narrative explaining large fluctuations and timing differences — this helps respond quickly if HMRC asks.
• Train staff: Ensure staff who interact with the accounting system understand MTD requirements and how to preserve evidence, especially when making manual adjustments.

Data Security and Confidentiality

Secure handling of data is important both for legal compliance and to maintain trust. Apply role-based access control, implement two-factor authentication for key accounts, encrypt backups and have a documented data retention and deletion policy.

6. Practical Audit-Ready Checklist & Templates

Use this checklist to assemble a standard audit pack for a single reporting period (e.g., a VAT period or a tax year period).

Sample Period Cover Sheet (template text)

Use this text as the basis for a one-page summary that accompanies exports:

Business: [Business Name] | VAT/UTR: [Reference] | Period: [Start Date]–[End Date]
Contact: [Name, role, email, phone]
Software used: [Accounting system and version]
Bridging/spreadsheets used: [Y/N] — if yes, list files and versions
Notes on unusual items: [Short narrative on large adjustments, one-off items or corrections]

7. Responding to an HMRC Enquiry or Audit

Receiving an enquiry letter or compliance check notice from HMRC can be stressful. Follow these steps to respond effectively.

1. Read the Notice Carefully

Identify the period under review, the documents requested, and the deadline. HMRC typically gives reasonable time but deadlines must be observed.

2. Appoint an Adviser if Needed

If you are unsure, appoint an accountant or tax adviser (you can authorise an agent online). An adviser will liaise with HMRC on technical matters and ensure a measured response.

3. Assemble the Audit Pack

Use the checklist above: consolidate the requested evidence, index it and create a clear narrative highlighting reconciliations and explanations for unusual items.

4. Communicate Clearly and Early

Contact the HMRC officer if you need a short extension or clarification. Communicating proactively often reduces pressure and prevents escalation.

5. Keep Records of Communications

Store copies of letters, emails and notes of telephone conversations. These records may be helpful if disagreements arise later.

6. Seek to Resolve Informally First

If HMRC raises adjustments, discuss the basis and provide supporting documents. Where a disagreement remains, your adviser can help prepare formal representations or appeals.

Note: Never destroy records after receiving an enquiry notice — retain all originals and digital copies until the matter is fully closed.

8. FAQs and Common Mistakes

Q: Does HMRC require all records to be kept only in one piece of MTD software?

A: No. HMRC requires digital records to be kept and for submissions to be made via compatible software. You may use multiple systems, spreadsheets or bridging tools but you must be able to produce an audit trail and show how data was consolidated. Document mappings and keep exports.

Q: How long must I keep digital records?

A: HMRC’s general expectation is that records are retained for several years (commonly six years for VAT and many tax records). Always confirm current statutory retention periods and keep longer if litigation or an ongoing enquiry is likely.

Q: What if I discover errors after submission?

A: Correct errors promptly through your software or by contacting HMRC where required. Keep documentary evidence of the correction and the reason why it was necessary. Transparent, timely corrections reduce penalties.

Common mistakes to avoid

• Relying on incomplete or unindexed spreadsheets with no version history.
• Failing to preserve original invoices and receipts or to scan them at the point of receipt.
• Ignoring user access logs and failing to remove former employee access.
• Lack of reconciling notes for unusual journals or adjustments.

9. How Tax Digital Can Help

At Tax Digital we specialise in Making Tax Digital compliance and provide practical, hands-on support to prepare for HMRC audits and enquiries. Our services include:

• MTD health checks — system audits to identify gaps and bridging risks.
• Audit pack preparation — export, index and deliver HMRC-ready evidence packs.
• Process design — create digital recording processes that meet HMRC functional compatibility expectations.
• Training and documentation — staff training on bookkeeping hygiene and MTD responsibilities.
• Ongoing accounting and compliance — bookkeeping, VAT submissions and representation during enquiries.

If you want a complimentary MTD readiness call or a bespoke audit-pack template for your business, contact us at hello@tax-digital.example or call 0207 000 0000. Our team of qualified accountants will guide you through the process and help you demonstrate robust MTD compliance to HMRC.

Final Checklist (Quick Reference)

• Confirm which taxes you file under MTD and applicable periods.
• Use MTD-compatible software and enable audit logs.
• Reconcile bank, VAT and ledger monthly.
• Maintain a single indexed audit pack per reporting period.
• Document bridging and spreadsheet processes and keep version histories.
• Retain records for statutory periods and do not destroy records under enquiry.

This article provides general guidance only and is not a substitute for professional advice. HMRC rules and MTD requirements can change — check the latest HMRC guidance or speak to your accountant for specific obligations.