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A COP9 investigation is one of the most serious civil enquiries opened by HM Revenue & Customs. Issued under Code of Practice 9 and the Contractual Disclosure Facility, it is used where HMRC suspect deliberate tax fraud.
If you have received a COP9 letter, you are being given a limited opportunity to disclose irregularities in exchange for protection from criminal prosecution. How you respond at this stage will determine the outcome of the entire investigation.
A COP9 investigation is opened by HMRC where they suspect deliberate tax fraud. It is conducted under the Contractual Disclosure Facility (CDF), as outlined by HM Revenue & Customs, which gives you the chance to admit irregularities in exchange for immunity from criminal prosecution.
You typically have 60 days to respond.
Failure to respond correctly can lead to:
Loss of control over the process
A full criminal investigation
Higher financial penalties
HMRC do not issue COP9 lightly. These investigations are triggered when there is strong evidence of deliberate behaviour.
Common triggers include:
In many cases, HMRC already hold significant information before opening the investigation.
The process follows a structured path:
1. Initial Decision (60 Days)
You must decide whether to accept the Contractual Disclosure Facility.
2. Outline Disclosure
A high-level summary of irregularities is submitted to HMRC.
3. Full Disclosure Report
A detailed report covering all deliberate behaviour, calculations, and supporting evidence.
4. HMRC Review and Negotiation
HMRC review the disclosure and negotiate penalties and settlement.
5. Settlement
The case concludes with agreed liabilities and penalties.
Each stage carries risk. Early mistakes often lead to higher costs later.
A COP9 investigation is civil, but it sits close to criminal territory.
If you:
HMRC can withdraw the offer and pursue criminal proceedings instead.
This is why specialist handling from the outset is critical.
Most COP9 investigations take between 12 and 24 months.
Complex cases involving multiple entities, offshore structures, or incomplete records can take longer.
The timeline depends heavily on the quality of disclosure and how efficiently the case is managed.
We take full control of the process from day one.
Our approach includes:
We focus on resolving cases efficiently while reducing stress and uncertainty.
We have handled a wide range of COP9 investigations, including:
Typical outcomes include:
Do not respond without advice.
Early decisions shape the entire investigation. Getting it wrong can significantly increase risk and cost.
Immediate steps:
The CDF is HMRC’s offer to settle a tax fraud investigation on a civil basis in exchange for full disclosure.
Not if the CDF is accepted and full disclosure is made. If rejected or mishandled, HMRC can pursue criminal proceedings.
Yes. COP9 investigations require technical disclosure, negotiation, and strategy. General accountants are rarely equipped to manage the process.
Penalties depend on behaviour, disclosure quality, and cooperation. Structured handling can significantly reduce penalties.
In many cases, yes. COP9 is typically opened after HMRC have gathered substantial information.
We offer confidential, no-obligation initial discussions.
If you are facing a COP9 investigation, contact us today to understand your position and the best way forward.
If you want to find out more about the process read our case study here
