HMRC Can Fine You £3,000 for This Record-Keeping Mistake. And Most Bookkeepers Don’t Know It

Under section 12B of the Taxes Management Act 1970, HMRC has the power to impose a penalty of up to £3,000 per tax year for failure to keep adequate records. Not for a late return. Not for underpaid tax. Specifically and solely for the inadequacy of the underlying records — even when the tax return itself was filed on time and the figures were broadly correct.

It doesn’t require fraud or deliberate concealment. A trader who throws away their bank statements after two years, relies on memory for cash income, or keeps no contemporaneous record of business mileage is potentially exposed to this penalty, and the burden of demonstrating adequate record-keeping falls on them, not on HMRC.

Most clients don’t know this exists. Many bookkeepers know the rules exist but have never seen HMRC enforce them directly, so the risk gets downplayed.

What records does HMRC actually require?

The requirement differs by taxpayer type, but the underlying principle is consistent. Records must be sufficient to support the figures in the return, and they must be retained for the required period.

For self-employed individuals and partnerships, HMRC requires:

• All receipts of income, like sales records, bank statements, cash income logs

• All business expenses, such as receipts, invoices, and any vouchers supporting the deduction claimed

• Business mileage records if a mileage deduction is claimed. This includes date, destination, purpose, and miles for each journey

• Stock and work in progress valuations at the year-end

• Records of any private use adjustments for mixed business and personal expenditure

• Bank statements for all accounts used in the business

For companies, the requirements are similar but the retention period is longer. It’s six years from the end of the accounting period, compared to five years after the 31 January filing deadline for sole traders. That five-year retention window catches out clients who believe they only need to keep records for one or two years.

When does HMRC actually impose the penalty?

The inadequate records penalty typically surfaces during an HMRC enquiry or compliance check, rather than as a standalone audit. When an inspector opens a self-assessment enquiry and requests supporting documentation, the inability to produce adequate records can trigger the penalty in addition to any tax adjustments arising from the enquiry.

HMRC can open an enquiry up to four years after the end of the tax year to which it relates for innocent error, and up to six years for careless error. That means a client who discards records after two years is exposed for a longer period than they think.

The five most common situations in which HMRC finds records inadequate

1. No mileage log for the full year

2. Cash income not separately recorded

3. Expenses claimed without receipts

4. Bank statements for personal accounts used for business not retained

5. No stock valuation at year-end

Cash-based businesses face the highest exposure

Businesses that handle significant volumes of cash (such as trades, hospitality, market traders, personal service providers) face the highest practical risk of inadequate records penalties. The absence of a paper trail for cash transactions is both more likely and harder to remedy after the fact. HMRC’s approach to cash businesses during enquiries includes till rolls, banking patterns, and lifestyle assessments. Where the records don’t support the declared income, the inadequate records penalty can land alongside a tax adjustment based on HMRC’s own estimate of turnover.

For bookkeepers and accountants serving cash-based clients, the most protective approach is active record-keeping guidance at the start of the engagement and regular check-ins throughout the year, not just at year-end when the absence of records becomes apparent. A client who doesn’t know they need to log cash income daily can’t be expected to do it; a client who’s been told clearly and given a simple method to do it has no excuse.

Digital record-keeping and MTD: how the rules are tightening

MTD IT changes the record-keeping landscape in a practical as well as a legal sense. The digital record-keeping requirement under MTD IT means that income and expenses must be recorded digitally as they arise, not reconstructed at year-end from memory or incomplete notes.

The connection between MTD IT record-keeping and adequate records compliance is direct. BrightBooks by Bright maintains the live digital records that satisfy both the MTD digital link requirement and the HMRC adequacy standard, giving clients a single record-keeping system that covers both obligations rather than two separate approaches.

What should accountants and bookkeepers tell their clients right now?

Three things, communicated clearly and in writing:

1. How long to keep records
   Five years after 31 January for sole traders. Six years for companies. Not two years. Not ‘a few years’. A specific number, applied consistently.

2. What counts as adequate
   Source documents, not summaries. Receipts for individual expenses, not a running total. A contemporaneous mileage log, not an end-of-year estimate.

3. What the consequence of inadequate records is
   Up to £3,000 per tax year, applied by HMRC during an enquiry, without needing to prove that any tax was underpaid. That framing, that the penalty is for the records themselves, not for underpaid tax — tends to land with clients in a way that abstract rules about retention periods don’t.

For more on managing HMRC enquiry risk across a self-assessment portfolio, see our post on how the new HMRC penalty points system works for MTD and self-assessment clients.

This content may have been developed with the assistance of AI tools. Content is reviewed by a member of the Bright team before publication. Guidance on legislation can be obtained from your industry body.