Understanding HMRC Code of Practice 9 (COP9)

What is Code of Practice 9 (COP9)?

HMRC uses COP9 in cases where it suspects a taxpayer’s behaviour has deliberately caused a loss of tax, such as knowingly submitting incorrect tax returns or withholding relevant information. COP9 is operated by HMRC’s Fraud Investigation Service (FIS), a specialist unit of fraud‑trained investigators.

Under COP9, HMRC offer a taxpayer the opportunity to enter the Contractual Disclosure Facility (CDF), a formal agreement in which the taxpayer admits to deliberate behaviour and commits to providing full, honest, and complete disclosure of all tax irregularities. In exchange, HMRC will agree not to pursue criminal investigations into the disclosed behaviour.

Taxpayers can voluntarily request that HMRC offer COP9 in instances where they know they have deliberately underdeclared a liability to tax. This is advantageous where taxpayers need the protection from criminal investigation that COP9 offers.

However, this protection is conditional: if HMRC later finds that the disclosure was incomplete or misleading, it reserves the right to escalate the matter to a criminal investigation. COP9 disclosures and investigations are high risk and require careful and expert management, with specialist advice highly recommended.

Key features of COP9

• Seriousness of allegation: COP9 is only opened where HMRC suspects fraud; the initial letter clearly states this.
• Civil investigation route: COP9 offers a civil route to settlement, avoiding criminal proceedings if handled correctly.
• Full disclosure requirement: Taxpayers must disclose all deliberate and non‑deliberate irregularities across all tax heads.
• Immunity from prosecution: Provided the disclosure is complete and accurate, HMRC will not criminally prosecute the disclosed issues. It is therefore an opportunity for those who have knowingly under-declared their tax liabilities, but there are several risks.

The COP9 process

1. HMRC issues the COP9 letter

The process begins when HMRC sends a COP9 letter accompanied by a pack explaining the allegation, the CDF offer, and templates for disclosure. This letter indicates HMRC’s reasons to suspect tax fraud, however, it does not need to prove its case at this stage.

2. The 60‑Day decision window

The taxpayer must respond within 60 days, choosing either to accept or reject the CDF contract. Accepting the CDF involves admitting deliberate behaviour; rejecting it carries the risk of HMRC continuing its fraud investigation without the guarantee of immunity.

3. The outline disclosure

If the taxpayer accepts the CDF, the next step is a written outline disclosure, which provides a narrative of all deliberate behaviours and associated irregularities. It must be honest, concise, and complete, as omissions can void the investigation’s civil status.

4. The full disclosure report

HMRC then expects a comprehensive disclosure report, including:

• A full explanation of behaviours;
• Reconstruction of financial records;
• Tax computations;
• Supporting evidence; and
• A signed statement of completeness

This process can involve multiple tax types, such as Income Tax, Corporation Tax, VAT, PAYE, Capital Gains Tax, and offshore matters, often spanning many years.

5. Meetings with HMRC

FIS officers may request meetings to clarify the disclosure and test the credibility of the information provided. These officers are trained to interrogate complex financial arrangements.

6. Resolution and settlement

If HMRC accepts the disclosure, the case proceeds to a civil settlement involving tax, interest, and penalties. In cases of full cooperation, publicity can usually be avoided.

COP9 is not a process to be navigated alone. It is a serious, high‑risk investigation requiring expert handling and strategic disclosure. With the right professional support, taxpayers can avoid criminal prosecution, regularise their affairs, and achieve a workable civil settlement.

How our tax disputes specialists support taxpayers through COP9

Facing a COP9 investigation can be overwhelming. HMRC strongly advises taxpayers to seek professional advice due to the complexity and consequences of the process. This is complex, specialist work and needs careful handling. We provide end‑to‑end specialist support, leaning on our extensive experience in COP9 and the CDF process.