What Is Code of Practice 9 (CoP9)?
Code of Practice 9 (COP9) is HMRC's most serious civil investigation procedure. It is issued when HMRC suspects that a taxpayer has committed deliberate tax fraud — either through deliberate understating of income, deliberate overclaiming of expenses or reliefs, or a systematic pattern of non-compliance.
Receiving a COP9 letter is an extremely serious matter. It means HMRC believes there is evidence of fraudulent behaviour and is offering you the opportunity to make a full disclosure under the Contractual Disclosure Facility (CDF) rather than pursuing criminal prosecution.
The Contractual Disclosure Facility (CDF)
The CDF is a contractual arrangement between the taxpayer and HMRC. Under COP9, you are given 60 days to decide whether to accept the CDF offer. If you accept, you must:
- Provide a signed certificate confirming you will make a complete and accurate disclosure
- Disclose all deliberate conduct that has led to a loss of tax
- Cooperate fully with HMRC throughout the process
- Pay all outstanding tax, interest, and penalties
In return, HMRC undertakes not to pursue criminal prosecution for the matters disclosed, provided the disclosure is complete and truthful.
What Happens If You Reject the CDF?
If you choose not to accept the CDF, or if you accept but later fail to make a complete disclosure, HMRC reserves the right to pursue the matter through criminal investigation. This could lead to prosecution and, in the most serious cases, custodial sentences.
The Investigation Process
Once the CDF is accepted, the process typically follows these stages:
- Outline Disclosure: An initial summary of the tax irregularities, submitted within 60 days of acceptance
- Formal Disclosure Report: A detailed report covering all tax years affected, the methodology used, and the full extent of the tax loss
- Verification: HMRC will verify the disclosure against their own information and may request further details
- Settlement: Agreement on the total tax, interest, and penalties owed
Why Expert Advice Is Critical
COP9 investigations are among the most complex and high-stakes tax matters a taxpayer can face. The consequences of mishandling a COP9 — whether by failing to disclose fully, missing deadlines, or providing inaccurate information — can be devastating.
At GSC Tax Consultancy, our specialists have extensive experience managing COP9 cases from initial receipt through to settlement. We provide:
- Immediate assessment of your position and realistic advice on options
- Preparation of the Outline Disclosure and Formal Disclosure Report
- Liaison with HMRC's Fraud Investigation Service on your behalf
- Negotiation of penalties to achieve the lowest possible settlement
- Complete confidentiality throughout the process
If you have received a COP9 letter, do not delay — seek specialist help immediately. Contact GSC Tax Consultancy for an urgent, confidential consultation.