The Common Issues That Can Raise an HMRC Investigation
Receiving a letter from HMRC can be enough to make any business owner nervous. However, an HMRC investigation does not automatically mean that you have done something wrong.
While some enquiries are selected at random, many arise because something in a tax return, VAT submission or business records prompts further questions.
The good news is that most of the common triggers are avoidable. Accurate record-keeping, consistent reporting, and a proactive approach to tax compliance can significantly reduce the risk of attracting unwanted attention.
What Is an HMRC Investigation?
An HMRC investigation, often referred to as a compliance check, is a review of your tax affairs to ensure the correct amount of tax has been declared and paid.
The review may focus on a specific area, such as a VAT return or expense claim, or it may involve a wider examination of your business records and tax history.
HMRC can investigate:
- Self-Assessment tax returns
- Corporation Tax returns
- VAT returns
- PAYE records
- Capital Gains Tax reporting
- Business expenses and deductions
In many cases, HMRC is simply seeking clarification or evidence to support information already submitted.
Poor Record Keeping
One of the most common causes of tax problems is poor record-keeping.
Most business owners do not deliberately submit incorrect figures. More often than not, bookkeeping falls behind, receipts are misplaced, or information is spread across multiple systems. Small errors then build up over time and eventually appear in tax returns.
For example, a missing sales invoice could result in an understatement of turnover. Lost receipts may result in expense claims that cannot be supported if HMRC requests evidence.
Businesses should maintain clear records of:
- Sales income
- Business expenses
- VAT transactions
- Payroll records
- Bank transactions
- Receipts and invoices
Good record keeping does more than satisfy a legal requirement. It provides the evidence needed to support every figure submitted to HMRC.
Reporting Inconsistencies
HMRC has access to information from a range of sources and can compare data across multiple tax submissions.
Problems often arise when the figures reported in one area do not match those reported elsewhere.
Examples include:
- Turnover on VAT returns differs from the annual accounts
- Payroll records not matching PAYE submissions
- Income figures that vary significantly from previous years
- Information that conflicts with third-party data
A single discrepancy may have a perfectly reasonable explanation. However, several inconsistencies can raise questions about the accuracy of the underlying records.
Regular reviews before submitting returns can help identify and correct issues before they become a problem.
Repeated Errors on Tax Returns
Mistakes happen. HMRC understands this.
However, repeated errors can suggest weaknesses in bookkeeping procedures or a lack of care when preparing returns.
Common examples include:
- Incorrect VAT treatment
- Missing income
- Misclassified expenses
- Frequent amendments to previously submitted returns
Where the same issues recur, HMRC may question whether reasonable care has been taken in preparing tax returns.
Unusually High Expense Claims
Claiming legitimate business expenses is an important part of managing tax liabilities. Problems arise when claims appear unusually high or difficult to justify.
Areas that often attract scrutiny include:
- Travel expenses
- Vehicle costs
- Home office claims
- Entertainment expenses
- Director expenses
Before making a claim, it is worth asking a simple question: could you clearly explain the business purpose of the expense if HMRC asked for evidence?
If the answer is unclear, the claim may need further review.
Large Changes in Income or Profit
Many business owners worry that a particularly successful year will automatically attract HMRC’s attention.
In reality, large increases or decreases in turnover and profit are not usually a problem if there is a genuine commercial reason behind them.
Questions are more likely to arise when figures appear inconsistent.
For example, turnover may remain broadly unchanged while expenses increase significantly, resulting in a sharp fall in profit. Equally, a business may report low profits year after year while directors continue to draw substantial amounts from the company.
Where major changes occur, keeping records that explain the reasons behind them can be invaluable if questions arise later.
Late Filing and Late Payments
Submitting a tax return late does not automatically trigger an HMRC investigation.
However, a pattern of missed deadlines, late payments and ongoing compliance issues can suggest wider problems within a business.
Late submissions often go hand in hand with incomplete records, rushed bookkeeping and avoidable errors.
Filing returns accurately and on time demonstrates good financial management and reduces unnecessary risk.
Cash-Based Businesses
Businesses that handle large volumes of cash often face greater scrutiny because cash transactions can be more difficult to track than electronic payments.
This can affect sectors such as:
- Hospitality
- Retail
- Construction
- Hair and beauty
- Market traders
This does not mean these businesses are automatically targeted. However, accurate record keeping becomes particularly important where cash forms part of normal trading activity.
Clear records help demonstrate that all income has been correctly declared.
Making Tax Digital and Compliance
Making Tax Digital is changing the way businesses keep records and report tax information.
As more businesses fall within the scope of MTD, maintaining accurate digital records is becoming increasingly important.
Businesses that leave bookkeeping until the end of the year often discover problems months after they occurred. By contrast, keeping records up to date throughout the year makes it easier to identify errors, reconcile transactions and prepare accurate returns.
In many cases, adopting digital record-keeping can reduce compliance risks and improve the overall quality of financial information.
How to Reduce the Risk of an HMRC Investigation
No accountant can guarantee that HMRC will never open an enquiry. However, there are several practical steps businesses can take to reduce the likelihood.
These include:
- Keeping records accurate and up to date
- Reconciling bank accounts regularly
- Retaining receipts and supporting documentation
- Reviewing tax returns before submission
- Filing returns on time
- Using suitable accounting software
- Seeking professional advice when uncertain
Many HMRC enquiries begin because of small issues that have been overlooked for months or even years. Regular reviews can help identify these problems before they attract attention.
Why Professional Advice Matters
Tax rules continue to evolve, particularly with the ongoing rollout of Making Tax Digital.
Many businesses speak to their accountant only once a year, when accounts are due. By that stage, errors may already have occurred, and opportunities to correct them may have been missed.
Regular support from an experienced accountant can help ensure records remain accurate, tax returns are prepared correctly, and potential compliance issues are identified early.
At Maynard Johns, we work with businesses across a wide range of sectors, helping them maintain accurate records, meet their tax obligations and stay prepared for future reporting requirements.
Frequently Asked Questions
What is the most common trigger for an HMRC investigation?
Poor record-keeping and inconsistencies between tax submissions are among the most common reasons HMRC raises questions about a business’s tax affairs.
Can HMRC investigate a business at random?
Yes. Some enquiries are selected randomly. However, many investigations are prompted by unusual figures, reporting inconsistencies or compliance concerns.
Does a large increase in profit trigger an HMRC investigation?
Not necessarily. Significant increases in profit are common in growing businesses. HMRC is more interested in whether the figures reported can be supported by accurate records.
Does Making Tax Digital reduce the risk of an HMRC investigation?
Making Tax Digital can help improve record-keeping and reduce errors, making it easier to prepare accurate tax returns and respond to HMRC enquiries.
How long should business records be kept?
Most businesses should retain tax records for at least six years, although some circumstances may require records to be kept for longer.