COP9 investigations and the Contractual Disclosure Facility

What is COP9?

Code of Practice 9 (COP9, sometimes written COP 9) is the code HMRC’s Fraud Investigation Service follows when it investigates suspected tax fraud through civil procedures. HMRC issues it in selected cases where it suspects tax fraud: that deliberate conduct has brought about a loss of tax. It is a civil procedure rather than a criminal one, but it is offered precisely because HMRC regards the matter as serious.

A COP9 letter means HMRC has not, at that point, started a criminal investigation. It does not mean fraud has been proved, and the code says HMRC will not normally explain its suspicions. COP9 covers almost every tax HMRC deals with, from income tax and VAT to PAYE, inheritance tax and excise duties. The offer is made to individuals: where a company is involved, HMRC can make it to the people responsible.

What is the Contractual Disclosure Facility?

The letter will offer you the Contractual Disclosure Facility (CDF). In broad terms, that is a contract: a complete and accurate disclosure of the deliberate conduct, made within the terms offered, in exchange for HMRC undertaking not to pursue a criminal investigation into the conduct disclosed. The terms require an outline disclosure within 60 days, a later formal disclosure, full co-operation including attending meetings, and payment of what is due.

HMRC will not offer the CDF on any other terms. The code also sets out the limits of the undertaking: it does not bind the police or regulators, does not cover offences that were not committed against HMRC, and protects only the person who accepts. Civil penalties can still be charged.

The COP9 letter and the 60-day deadline

The letter comes with a copy of the code, an acceptance letter, a rejection letter and HMRC’s outline disclosure form. The code gives 60 days from the date you receive the offer to accept or reject it, and HMRC’s instructions to its investigators say the letter should state the date the offer ends. HMRC’s guidance says these are calendar days, and that the deadline can be extended only in exceptional circumstances; simply running out of time does not qualify. An acceptance must arrive with a valid outline disclosure inside the same 60 days.

During that period HMRC will not discuss your tax affairs until you have said how you wish to proceed, although it can still collect debts.

COP8 or COP9: which letter is it?

Both codes are used by HMRC’s Fraud Investigation Service, and both are civil. COP8 covers its civil investigations where COP9 is not used, typically where HMRC believes there may be a significant loss of tax; it carries no allegation of fraud and no CDF. COP9 is used where HMRC suspects fraud. The two are handled very differently, and a COP8 enquiry can move to COP9 if HMRC comes to a different view of the conduct. If you are unsure which you have received, our COP8 page and the guide toidentifying your HMRC letter are the place to start.

Why the first move matters more here than anywhere else

Accepting the offer, rejecting it, and allowing the response period to lapse each carry different and significant consequences. So does a partial or inaccurate disclosure made inside the facility, which can remove the protection the facility was entered into for.

There is no version of this in which acting quickly without advice is the safer option. The response window exists to be used for taking advice, not for drafting.

Accepting, rejecting or not replying: what HMRC’s code says

This is what the code says, in HMRC’s terms. It is not a recommendation either way: which response is right depends entirely on the facts.

Accepting

Accepting means returning the acceptance letter with a valid outline disclosure. It is an admission that deliberate behaviour brought about a loss of tax, which the code says lets HMRC seek tax, interest and penalties forup to 20 years, or longer in exceptional cases. If the terms are met, HMRC undertakes not to start a criminal investigation into the frauds disclosed. The code lists when HMRC can still start one after an acceptance: if the outline disclosure is invalid, since HMRC is then not bound by the contract; into any suspected frauds the outline disclosure leaves out; into a false statement or document, or incorrect or incomplete formal disclosure documents, as offences in themselves; and if the admission is withdrawn without good reason.

Rejecting

Rejecting means signing and returning the rejection letter within the 60 days. The code says this is for someone who genuinely believes they have not brought about a loss of tax through deliberate behaviour. HMRC says it will consider any explanation or documents sent with the rejection and, if it verifies and accepts the explanation, will confirm in writing that it no longer suspects tax fraud. If its suspicions are not allayed, it may start a criminal investigation. The rejection letter and anything sent with it can be used as evidence, and HMRC’s guidance to its investigators says a rejection stands even if the person changes their mind within the 60 days.

Not replying

The code treats silence after 60 days, or an acceptance that is not completed properly, as a rejection, and says HMRC may then begin a criminal investigation. HMRC’s guidance page says it will begin either a civil or a criminal investigation.

If you do not believe your conduct was deliberate

A COP9 letter means HMRC suspects tax fraud, not that it has been established. The code describes tax fraud as dishonest, deliberate behaviour that cannot be committed by accident, and says the CDF is not for someone with only careless errors to disclose. Whether behaviour was deliberate is a judgement on the facts, and HMRC’s view of them may differ from your own. If the facts do not support HMRC’s suspicion, the response needs particular care, because what is said at this stage frames everything that follows. It is exactly the kind of decision that should be made with advice rather than alone.

What happens in a COP9 investigation

Every matter differs, but a COP9 investigation broadly moves through these stages.

1. The offer letter. HMRC offers the Contractual Disclosure Facility, with 60 days from receipt to respond.
2. The response. Accepting means making an outline disclosure of the deliberate conduct. Rejecting, or not responding, leaves HMRC free to decide how to proceed, which can include a criminal investigation.
3. The opening meeting. HMRC will usually ask to meet.
4. The disclosure report. In most cases a full report covering all irregularities, not only those HMRC raised, with supporting calculations.
5. The formal disclosure. Four signed documents on HMRC templates, including a certificate of full disclosure and a statement of assets and liabilities.
6. Settlement. For direct taxes, normally a contract settlement covering the tax, interest and penalties; VAT and other indirect taxes are settled by assessment.

The outline disclosure: what it must contain

The outline disclosure is made on HMRC’s own form. Precise details are not expected if they cannot reasonably be obtained within the 60 days, but it must be an honest description, to the best of your recollection. Simply stating that deliberate behaviour caused a loss of tax is not enough. For each loss, the code asks what was done and how; who else was involved, with names, addresses and tax references where known; any companies, trusts or nominees used, and in what capacity; how you benefited; and over what period.

It should also set out careless errors and other non-deliberate irregularities in a separate section, give an indication of the amounts involved with any estimates flagged, and describe the records available. One that covers only non-deliberate behaviour is invalid, and HMRC’s guidance gives other examples: a missing signature, late arrival, or an admission contradicted elsewhere in the form. HMRC also expects a payment on account with it, which the code says reduces the interest building up.

The opening meeting

After an outline disclosure or a rejection, or once the 60 days pass without a reply, HMRC may ask for a meeting and will explain its purpose. After an acceptance it usually covers the outline disclosure and the scope of the disclosure report; after a rejection, how the investigation will proceed. If you have accepted the CDF, its terms include personally attending the meetings HMRC asks for, and you can bring an adviser. The code says what is said can be used to work out tax and penalties and as evidence in legal proceedings.

The disclosure report, the certificates and the statement of assets

Where more work is needed after the outline disclosure, which the code says is so in most cases, a disclosure report follows. Even if an adviser prepares it, the code makes you responsible for its content and its deadline. It must cover every irregularity across the whole period of the deliberate behaviour, separate deliberate from non-deliberate, state the correct tax and show how each figure was worked out, with summaries of the tax, interest and penalties due.

The CDF’s terms end with a formal disclosure: four documents on HMRC templates, which must not be altered.

• a certified statement of worldwide assets and liabilities
• a certificate and schedule of all financial accounts operated
• a certificate and schedule of all financial cards operated
• a certificate of full disclosure, signed in front of a witness

The first three normally accompany the report; HMRC’s guidance says the certificate of full disclosure follows once the figures are agreed. The code warns that a false certificate can lead to a criminal investigation and be used in criminal proceedings.

Before then, HMRC agrees the settlement of tax, interest and penalties. The code says you will be invited to make a financial offer, payable in full or under an agreed payment plan. Where agreement cannot be reached, HMRC makes formal assessments, which can bereviewed and appealed.

How long does a COP9 investigation take?

After the first 60 days there is no fixed timetable, and we will not quote a typical length, because it depends on the case. The timetable for the disclosure report is agreed case by case, according to how complex the work is, how much there is and how easily the information can be obtained. HMRC’s guidance to its investigators says there is no fixed period for the report, that they should seek no more than six months without treating six months as standard, and that longer is exceptional. HMRC then checks the report before the figures are agreed, and the code says that making the formal disclosure does not by itself end the investigation.

How penalties are worked out under COP9

COP9 has no penalty scale of its own. Penalties follow the normal legislation: a percentage of the tax lost, reduced according to the quality of the disclosure. As the code puts it, the more you co-operate, the lower the penalty. For inaccuracies in a return, the ranges for deliberate behaviour are:

A disclosure made after HMRC has written will normally be prompted, and a deliberate failure to notify HMRC uses the same ranges. Offshore matters can carry higher percentages; the code says some penalties can exceed 200% of the tax. Older years fall under earlier penalty rules that work differently, and interest is charged on top. OurHMRC penalty calculator shows how the range and the reduction combine for an onshore inaccuracy, and our guide tocareless, deliberate and concealed penalties explains the rules.

Can HMRC publish your details?

HMRC can publish the name, address and business of someone with a penalty for deliberate behaviour where the tax at stake (the potential lost revenue) exceeds £50,000; the threshold was £25,000 until 2 October 2026. It cannot publish if the penalty was reduced by the full amount allowed for the quality of the disclosure (for offshore matters, only where that disclosure was unprompted), and it must first give the person a chance to make representations. Details can appear only once the penalty is final, which for a contract settlement is when the contract is made, and for no more than a year. See our guide toHMRC’s deliberate tax defaulters list.

Can you use the CDF without an HMRC letter?

Yes. Someone who needs to disclose tax fraud can ask HMRC to consider them for a CDF contract using form CDF1, without waiting to be contacted. HMRC does not have to offer one, and cannot if the person is already involved in a criminal investigation by HMRC or another agency, such as the police. Anyone already dealing with HMRC on another tax matter who wants to be considered should tell the officer handling it. The CDF is only for tax fraud: HMRC says it must not be used for errors, mistakes or avoidance schemes unrelated to fraud. For errors, see voluntary disclosures. Which route fits is a judgement on the facts, best made with advice before anything is sent.

Is a COP9 investigation criminal?

No. COP9 is a civil procedure, and a COP9 letter is not a criminal step in itself. But the code reserves HMRC’s complete discretion to start a criminal investigation, carried out separately from COP9, including at the points set out above. An arrest, a search under a warrant or an invitation to an interview under caution belongs to a criminal investigation; if any of those happens, contact a criminal defence solicitor before saying anything to HMRC. We are accountants and handle the civil side; we do not act for anyone in a criminal investigation. Our guide to whetheran HMRC investigation is criminal or civil explains the difference.

Why specialist help matters

HMRC’s own code strongly advises taking independent professional advice before responding, and notes that many people appoint an adviser who specialises in COP9 alongside their usual one. The reasons are practical: a decision and, if the offer is accepted, an outline disclosure within 60 days, then a report that must be investigated, calculated and presented to a standard HMRC will test. You remain personally responsible for what is sent on your behalf.

What we do

• Read the letter and confirm precisely what has been offered and by when
• Establish the facts before any position is taken with HMRC
• Advise on the response in light of your actual circumstances, not a general rule
• Where the facility is entered into, prepare the disclosure to the standard required
• Manage correspondence and meetings through to settlement
• Tell you plainly if the matter needs specialist counsel rather than us

What we will not do

We will not advise you to accept or reject a CDF offer on the basis of anything short of the facts. We will not tell you what the outcome will be, because nobody honestly can. And we will not take on a matter that belongs with a specialist investigations practice or with counsel.

Further reading

• Criminal or civil? How HMRC deals with tax evasion
• HMRC’s deliberate tax defaulters list
• HMRC penalties for careless and deliberate errors
• How far back can HMRC investigate?
• COP8 investigations
• Voluntary disclosures to HMRC
• Appealing an HMRC penalty