Handling an HMRC Investigation or Enquiry

Receiving a letter from HMRC opening an enquiry into your tax return is one of the most stressful events a business owner can face. The instinct is often to panic, then to hand everything over to the accountant and hope for the best. A fractional Finance Director provides something far more valuable: structured, informed management of the enquiry process from the moment the letter arrives to the point of resolution.

Yes — supporting a business through an HMRC investigation or enquiry is firmly within a fractional FD's remit. In fact, having an FD alongside your accountants during an HMRC enquiry is one of the clearest demonstrations of why the role adds value that is difficult to quantify in advance but immediately apparent when the situation arises.

Types of HMRC Enquiry and Investigation

It is important to understand that not all HMRC enquiries are equal in their severity or scope. Understanding what type of enquiry your business is facing is the first step to managing it effectively.

• Section 9A enquiry (self-assessment) — HMRC has the right to enquire into any self-assessment return within 12 months of the filing date (or longer where there has been late filing or where there is a suspicion of fraud). These can be aspect enquiries (focused on specific items) or full enquiries (covering the return in its entirety)
• Schedule 18 enquiry (corporation tax) — the equivalent of a Section 9A enquiry for companies, with similar scope and timelines
• VAT inspection — a formal compliance check of your VAT records and returns, which can range from a routine desk review to a detailed visit to your premises
• PAYE compliance check — a review of your employer records, RTI submissions, P11D filings and payroll processes
• Civil investigation of fraud — the most serious form of HMRC investigation, reserved for cases where HMRC suspects deliberate tax evasion; these involve specialist investigators and carry the risk of criminal prosecution
• Code of Practice 9 (COP9) — a formal fraud investigation procedure where HMRC offers a contractual disclosure facility as an alternative to criminal prosecution; navigating this requires specialist legal advice in addition to the FD's support

The FD's Role During an HMRC Enquiry

The fractional FD provides the coordination, governance and commercial intelligence that transforms an HMRC enquiry from a chaotic, reactive experience into a managed, strategic process. This involves several distinct functions.

Initial Assessment and Strategy

Upon receiving an HMRC enquiry notice, the FD's first task is to assess the scope and likely cause of the enquiry. What aspect of the return or accounts has triggered HMRC's interest? Is this a routine random check or is there a specific compliance risk that has been flagged? What is the likely worst-case exposure if HMRC's suspicions are confirmed? What is the strength of the business's position on each disputed point?

This initial assessment enables the FD to develop a response strategy — determining which issues to concede promptly, which to contest robustly, and whether a voluntary disclosure of any historic errors might be appropriate to reduce penalties. The strategy is developed in close coordination with your accountants and, where appropriate, specialist tax dispute advisers or tax barristers.

Preparing and Reviewing Responses to HMRC

Every communication with HMRC during an enquiry is consequential and must be carefully considered. Responses that are too narrow can appear evasive; responses that are too expansive can inadvertently open new lines of enquiry. The FD reviews every substantive communication with HMRC before it is sent, ensuring that responses are accurate, appropriately scoped, and consistent with the agreed strategy.

This includes preparing or reviewing schedules of figures, explanations of accounting treatments, and supporting documentation. The quality and organisation of supporting information significantly influences HMRC's assessment of whether management is co-operative and trustworthy — which in turn affects penalty levels if any tax is found to be underpaid.

"HMRC opened a full corporation tax enquiry following an R&D tax credit claim. Without our FD coordinating the response, I think we would have panicked and settled far too quickly. Instead, we had a clear strategy, responded methodically, and ultimately HMRC accepted our position on the R&D claim in full. The only adjustment was a minor unrelated point worth a few hundred pounds."

Minimising Penalties Through Cooperation

Where HMRC identifies an underpayment of tax, the level of penalty applied is directly influenced by the quality of the taxpayer's cooperation throughout the enquiry. HMRC's penalty regime distinguishes between prompted and unprompted disclosures, and between deliberate, careless and non-deliberate behaviour. Penalty rates range from 0% (for unprompted disclosures of non-deliberate errors) to 100% or more of the tax due (for deliberate offshore evasion).

A fractional FD ensures that cooperation with HMRC is genuine, consistent, and well-documented throughout the enquiry, maximising the reduction in penalties available. Where historic errors exist, the FD coordinates a voluntary disclosure that is timely and comprehensive, demonstrating good faith and securing the most favourable penalty position available.

Preventing Future Investigations

Once an enquiry is resolved, the fractional FD undertakes a thorough review of the compliance processes that gave rise to the issue. If the enquiry identified genuine errors, those errors signal weaknesses in your financial controls or processes that must be remediated. If the enquiry was triggered by an anomaly that HMRC investigated but found to be correct, the FD will nevertheless consider whether your record-keeping and disclosure processes can be strengthened to reduce the risk of future selection.

This preventative work is ultimately the most important outcome of an HMRC investigation — the identification and remediation of the underlying vulnerability. By ensuring your VAT, PAYE, corporation tax and other obligations are managed with the same rigour described in our articles on VAT compliance and PAYE compliance, a fractional FD reduces the probability of an HMRC enquiry arising in the first place.