Code of Practice 9 is issued by HMRC’s Fraud Investigation Service when it suspects that tax has been lost through deliberate fraud. It comes with an offer of the Contractual Disclosure Facility: admit the deliberate conduct and disclose it in full, and HMRC undertakes not to start a criminal investigation into the fraud you have disclosed. You have 60 days from receiving the offer to accept or reject it. No reply is treated as a rejection. HMRC itself strongly advises taking independent professional advice before responding.

A COP9 letter is not a compliance check that has escalated. It is a different process, run by a different part of HMRC, with a contract at the centre of it and a criminal investigation as the alternative. If one arrives, everything else waits.

What COP9 is

Code of Practice 9 explains how the Fraud Investigation Service carries out civil investigations in cases where HMRC suspects fraud. The choice HMRC has made by issuing it is significant: it has decided, for now, to investigate civilly rather than criminally, and it is offering you a route to keep it that way.

What the Contractual Disclosure Facility offers

The CDF is a contract. On your side, you admit that you have brought about a loss of tax through deliberate conduct and you disclose the irregularities in full. On HMRC’s side, it undertakes not to commence a criminal investigation into the suspected fraud connected with the behaviour you have disclosed.

The protection is bounded by what you disclose. An incomplete disclosure does not buy protection for what was left out, which is why the quality of the disclosure work matters more than its speed.

The 60 day clock

You have 60 days from receipt of the CDF offer to accept or reject it. If you do not respond within that period, HMRC treats the silence as a rejection.

Sixty days sounds generous. It is not, if the disclosure requires reconstructing years of records, and it is not if you spend the first three weeks deciding whether to take advice.

What happens if you reject or ignore it

Rejecting the offer, or failing to respond within the 60 days, means HMRC investigates by other means. HMRC states plainly that it may commence a criminal investigation into the tax fraud it suspects you have committed.

Rejection is a legitimate answer where there has been no deliberate conduct. It is not a delaying tactic, and it should not be given without advice.

How COP8 differs

Code of Practice 8 also comes from the Fraud Investigation Service, but it is used for cases where serious fraud is not suspected: bespoke avoidance arrangements and complex or technical disputes. HMRC’s own manual title for identifying COP8 cases states this directly.

A COP8 case can be reclassified as a COP9 case, but only where new information or facts emerge that justify it, with internal authority and a documented audit trail. The reverse also happens.

Why this is not a normal enquiry

The usual advice about compliance checks does not transfer. In a standard enquiry the worst realistic outcome is tax, interest and a penalty. Here, criminal investigation is expressly on the table, the process is contractual, and the deadline is fixed.

HMRC’s own guidance strongly advises seeking independent professional advice before responding to a CDF offer. That is HMRC telling you not to do this alone, and it is worth taking at face value.

Common questions

How long do I have to respond to a CDF offer?

Sixty days from receipt. Failing to respond in that window is treated by HMRC as a rejection of the offer.

What happens if I reject the Contractual Disclosure Facility?

HMRC investigates by other means and may commence a criminal investigation into the fraud it suspects.

Does accepting the CDF mean admitting fraud?

Yes. Acceptance involves admitting that you brought about a loss of tax through deliberate conduct and disclosing the irregularities. That is precisely why HMRC advises taking independent professional advice before responding.

What is the difference between COP8 and COP9?

Both come from HMRC’s Fraud Investigation Service. COP9 is used where fraud is suspected and carries the CDF offer. COP8 is used where serious fraud is not suspected, typically for bespoke avoidance and complex technical disputes.

Does tax fee protection insurance cover a COP9 investigation?

Do not assume it does. Cover for deliberate conduct and for fraud investigations is treated very differently from cover for a routine compliance check, and this is a case where the wording needs reading before anything is said to HMRC. A COP9 also needs a specialist adviser rather than general enquiry representation.

Related guides

This page explains what HMRC Code of Practice 9 and the Contractual Disclosure Facility are. It is general information, not tax advice or legal advice, and it does not describe the terms of any particular insurance policy. If you have received a COP9 letter, take specialist advice immediately.

Solar Insurance Services (Medway) Limited is registered in England and Wales, company number 05439438, and is authorised and regulated by the Financial Conduct Authority, firm reference number 459582.

Sources: HMRC Code of Practice 9 (from 14 June 2023); HMRC guidance on admitting tax fraud using the Contractual Disclosure Facility; HMRC Fraud Investigation Service Code of Practice 8; HMRC Technical Teams Operational Guidance TTOG3420 and TTOG3430.