What to do when you’re facing a COP9 Investigation

Posted: 2nd October 2025

There’s a specific kind of fear that sets in when HMRC notifies you of an investigation under Code of Practice 9 (COP9). This isn’t just about a tax query; it’s a formal suspicion of deliberate tax fraud. HMRC may believe you have understated income, overstated expenses, or deliberately concealed information to reduce your tax liability.

What Is COP9?

COP9 is HMRC’s way of saying they suspect serious tax fraud, but they are giving you the chance to make a full disclosure to essentially start a with a clean slate. It is issued by the Fraud Investigation Service (FIS) when HMRC believes there has been deliberate wrongdoing. Along with the COP9 letter, taxpayers are offered the Contractual Disclosure Facility (CDF).

The CDF allows you to admit to deliberate tax fraud and make a complete disclosure. In return, HMRC grants immunity from criminal prosecution for what you disclose. However, if you fail to make a full and accurate disclosure, HMRC reserves the right to pursue a criminal investigation.

Taking Action

Once HMRC issues a COP9 letter, you have 60 days to decide whether to accept or reject the CDF offer.

Accepting: You admit to deliberate behaviour and enter into the CDF process, gaining protection from criminal prosecution, provided your disclosure is complete.

Rejecting: HMRC may continue their investigation, leaving the risk of prosecution open.

This is a highly sensitive stage. Immediate action is required, and expert guidance is essential.

Outline Disclosure

We assist in preparing your initial disclosure to HMRC, ensuring it reflects the reality of your situation while protecting you from unnecessary exposure.

At this stage, you don’t need every detail, but you must acknowledge that deliberate errors have occurred. You signal your willingness to cooperate fully with HMRC. This lays the groundwork for the full disclosure report to follow. Your initial disclosure is a crucial step in demonstrating good faith and shaping the path forward.

HMRC Review & Settlement

Once a disclosure report is submitted, HMRC undertakes a forensic review of this. They will:

• Examine every aspect of your disclosure.
• Request further information or clarification.
• Enter into negotiations on tax liabilities, interest, and penalties.

Eventually, this process concludes with a settlement agreement, which provides finality and closure to the investigation.

The Human Side of COP9

Clients often arrive at the start of a COP9 investigation feeling overwhelmed, anxious, and fearful. It is not uncommon for individuals caught up in these cases to have made mistakes because of poor advice or misunderstandings of complex tax rules, not because they set out to defraud HMRC.

Our role is not just technical but also supportive. We stand alongside our clients throughout the process, offering both expertise and reassurance. With the right guidance, mistakes can be corrected, and fair settlements can be reached.

It’s important to remember: HMRC’s ultimate goal is to recover tax, not to ruin lives. That said, if HMRC overstep their legal powers, we are ready to challenge them. A process built on honesty, transparency, and mutual respect usually leads to the best outcomes.

How We Can Help

If you have received a COP9 letter and don’t know where to start, NHD Tax Solutions can help. We will:

• Review your position in detail.
• Prepare the necessary disclosure to HMRC.
• Work to minimise potential penalties.
• Guide you through every step of the process with expert guidance. 

We are the team you need to navigate HMRC’s enquiries efficiently, effectively, and with confidence.