HMRC Tax Investigations: How to Prepare – Goodwille

An HMRC tax investigation can be one of the most stressful and time-consuming situations a business faces. Whether it starts with a routine compliance check or a targeted enquiry into a specific area of your tax affairs, the process demands careful handling, accurate records, and in most cases, professional advice from the outset.

At Goodwille, we have extensive experience supporting international businesses through HMRC enquiries. With nearly 30 years of experience and more than 2,000 overseas companies supported across a wide range of sectors, we know what HMRC looks for, what triggers an investigation, and how to respond in a way that protects your position.

This article sets out how HMRC tax investigations work, what types exist, and how your business can prepare.

 

What Triggers an HMRC Tax Investigation?

HMRC uses a combination of data analysis, random checks, and specific red flags to decide which businesses and individuals to investigate.

Not every investigation follows a complaint or a suspected fraud. Some are entirely random, and others are prompted by inconsistencies in data that HMRC’s systems flag automatically.

Common red flags that can prompt HMRC to open an investigation include:

• Significant differences between declared income and lifestyle or business activity
• Expenses that appear disproportionate to the size or type of business
• Tax returns filed late or with figures that fall outside industry norms
• Bank statements or accounts that do not align with submitted tax calculations
• A history of errors or amendments to previous tax returns
• Businesses that are VAT registered but show patterns inconsistent with their sector

HMRC also receives data from third parties, including banks, other government departments, and international tax authorities, and uses that data to cross-reference what taxpayers report.

 

Types of HMRC Tax Investigations

HMRC uses several different types of investigation depending on the nature of the concern, and the type it opens will determine how broad the process is and what records you need to provide.

 

Aspect Enquiry

An aspect enquiry focuses on a particular aspect of a tax return rather than the whole picture. HMRC may have a question about a specific expense, a single income source, or one element of a self-assessment tax return.

While narrower in scope than a full enquiry, an aspect enquiry can still develop into something broader if HMRC finds further information that raises additional concerns.

 

Full Enquiry

A full enquiry covers the entire tax return and all underlying business records. HMRC will request access to accounts, bank statements, invoices, payroll records, and any other documentation relevant to the taxpayer’s tax position for the period under review.

Full enquiries are more common where HMRC has identified a significant risk or where previous aspect enquiries have uncovered wider issues.

 

Random Checks

HMRC carries out random checks on a proportion of tax returns each year, regardless of whether there is any specific reason to suspect an error. These compliance checks are a normal part of HMRC’s approach and do not necessarily indicate that anything is wrong.

That said, they still require a thorough and timely response.

 

Criminal Investigations

Where HMRC suspects deliberate behaviour, tax evasion, or criminal activity, it can escalate beyond a civil enquiry and open a criminal investigation. HMRC’s Fraud Investigation Service handles criminal investigations and can result in criminal prosecution.

The threshold for criminal investigation is higher than for a standard enquiry, but businesses involved in tax fraud or serious tax avoidance face a significant risk of criminal powers being used against them.

 

The Contractual Disclosure Facility

The Contractual Disclosure Facility (CDF) is the mechanism HMRC uses when it suspects deliberate tax fraud. Under the CDF, HMRC writes to a taxpayer and allows them to disclose unpaid tax and cooperate with the investigation in exchange for immunity from criminal prosecution.

Accepting the CDF means acknowledging that deliberate behaviour has occurred, so any decision to accept or reject it should only be made with specialist legal and accountancy advice. Rejecting the CDF means HMRC may proceed with a criminal investigation.

 

Information Notices

As part of an HMRC investigation, HMRC can issue a formal information notice requiring a business or individual to provide specific documents or data by a set date. Failure to comply with an information notice can result in additional HMRC penalties, and in serious cases, further legal action.

It is important to respond to information notices accurately and on time, and to take professional advice before providing documents that could affect your tax position or expose additional issues.

 

 

Red Flags HMRC Looks For

Understanding what draws HMRC’s attention is one of the most practical steps a business can take. Beyond the triggers already mentioned, HMRC pays particular attention to:

• Cash-intensive businesses where income is harder to verify
• Businesses with expenses that are unusually high relative to revenue
• Directors or shareholders whose personal expenditure appears inconsistent with declared income
• Tax returns where figures change significantly year on year without a clear explanation
• Businesses in sectors that HMRC has identified as higher risk for non-compliance

Maintaining clean, well-organised business records throughout the year is the most straightforward way to reduce exposure if HMRC opens an enquiry.

 

How Far Back Can HMRC Investigate?

The time limit for HMRC to open an enquiry into a tax return is generally 12 months from the filing date. Beyond that, HMRC can use discovery assessments to go back further where it believes there has been an error or omission. The time limits are:

• 4 years where the error was innocent
• 6 years where there has been careless behaviour
• 20 years where fraud or deliberate behaviour is involved

For businesses that have operated in the UK for several years, this means that records from well before the current period may need to be produced if HMRC opens a criminal investigation or uses its extended powers.

 

How to Prepare for an HMRC Tax Investigation

The best preparation for an HMRC investigation is good compliance throughout the year. Practically, that means:

• Keeping accurate and complete business records, including bank statements, invoices, contracts, and payroll data
• Filing all tax returns and accounts on time and with accurate figures
• Retaining records for at least six years, and longer where there is any potential risk of a historical enquiry
• Responding to any HMRC requests promptly and fully
• Taking professional advice at the first sign that HMRC is looking at your affairs, rather than waiting to see how things develop

When HMRC opens an enquiry, the way a business responds in the early stages has a significant bearing on how the investigation develops, how long it takes, and what the final costs and penalties amount to.

 

HMRC Penalties and Additional Tax

Where an investigation finds that a business has paid insufficient tax, HMRC will seek to recover the unpaid tax along with interest and penalties.

The level of HMRC penalties depends on the nature of the behaviour involved:

• Prompted disclosure with no deliberate behaviour: lower penalty rates apply
• Unprompted disclosure: penalties are reduced further
• Deliberate behaviour: penalties can reach 70% of the additional tax owed
• Deliberate behaviour with concealment: penalties can reach 100% of the additional tax owed

Penalties are also affected by the degree to which a taxpayer cooperates with HMRC during the investigation. Full cooperation, accurate disclosure, and prompt responses all work in a business’s favour.

 

How Goodwille Can Assist

An HMRC tax investigation is not something to navigate alone. The process is time-consuming, technically demanding, and the costs of getting it wrong can be substantial, with additional tax, interest, and penalties all in play.

Goodwille’s finance and corporate governance teams work alongside specialist legal and accountancy professionals to support clients through every stage of an HMRC investigation.

From responding to an initial information notice or compliance check, to managing a full enquiry or advising on the Contractual Disclosure Facility, we provide the expert guidance and practical support that international businesses need to protect their position.

If HMRC has been in contact about your tax affairs, or if you want to review your business records and compliance position before any issues arise, get in touch with the Goodwille team

 

Frequently Asked Questions

Here are some of the most common questions we receive about HMRC tax investigations.

 

What is the difference between tax avoidance and tax evasion?

Tax avoidance means arranging your affairs in a way that reduces your tax liability within the law, though HMRC actively challenges arrangements it considers aggressive or artificial.

Tax evasion means deliberately concealing income, providing false information, or failing to declare tax owed. Tax evasion is a criminal offence and can result in criminal prosecution, fines, and imprisonment.

 

How long does an HMRC tax investigation take?

The length depends on the type and complexity of the investigation. An aspect enquiry into a particular aspect of a return can be resolved within months.

A full enquiry into several years of business records can take considerably longer, and a criminal investigation by the Fraud Investigation Service can run for years. Taking professional advice early and responding promptly to HMRC requests helps keep the process moving.

 

Does HMRC investigate every tax return?

No. HMRC selects returns for investigation through a combination of random checks, data matching, and risk-based criteria. The majority of tax returns are processed without any enquiry.

That said, the risk of investigation is higher for businesses in certain sectors, for returns that fall outside industry norms, and for taxpayers with a history of errors or late filing.

 

What should a business do when HMRC opens an investigation?

The first step is to take professional advice before responding to anything. The way a business responds at the outset sets the tone for the entire investigation. A specialist accountant and, where criminal activity is alleged, a legal team should be involved from the start.

Documents should not be destroyed or altered, and all HMRC requests should be handled through an adviser rather than directly, where possible.

 

Can HMRC investigate a dissolved company?

Yes. HMRC can investigate the tax affairs of a dissolved company and can apply to have it restored to the register if it needs to pursue unpaid tax or conduct a criminal investigation. Directors of dissolved companies remain personally exposed where deliberate behaviour or fraud is involved.