What is the Contractual Disclosure Facility?
Answered 17 March 2026
HMRC Guidance / Practice
The Contractual Disclosure Facility (CDF) is HMRC's civil investigation procedure for cases of suspected tax fraud, operated under Code of Practice 9 (COP9). Here is how it works:
Purpose and Context
The CDF is the mechanism through which HMRC investigates suspected tax fraud using civil (rather than criminal) procedures. It sits at the core of HMRC's compliance strategy to encourage voluntary disclosure. It is HMRC's main tool for investigating cases of suspected tax fraud using civil procedures, though it also opens the possibility of a criminal investigation at certain points.
How the CDF Works
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The Offer: HMRC issues COP9 to the taxpayer together with an offer of a contractual arrangement. The offer is made strictly on the terms of the current edition of Code of Practice 9. Critically, the offer letter must not indicate the reasons why the case has been registered for investigation, and HMRC will not disclose the detail of its evidence or concerns at the outset.
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The Customer's Response (60 days): Once COP9 is issued, the customer has 60 days to choose one of two options:
- Accept the offer of a contract (the CDF); or
- Formally reject the offer.
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Acceptance: A valid CDF agreement can only be created by the customer accepting the standard offer on HMRC's terms — no other terms are possible. By signing the acceptance letter, the customer undertakes to make both an Outline Disclosure and a Formal Disclosure.
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Outline Disclosure: This must be submitted within the same 60-day period and must contain:
- A brief description of the frauds committed;
- A formal admission of deliberately bringing about a loss of tax;
- Any non-fraudulent irregularities; and
- Any proposals for a payment on account.
The Outline Disclosure is essential to the CDF — failure to make one means the contractual undertaking has not been met.
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The Key Contractual Protection: In return for a valid Outline Disclosure, HMRC will not commence or continue a criminal investigation for offences disclosed in the Outline or Formal Disclosure. However, this protection only covers what is actually disclosed — any fraud not included in the Outline Disclosure remains at risk of criminal investigation or significantly higher penalties.
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Formal Disclosure: As part of a valid CDF, the customer must also submit a Formal Disclosure, which consists of:
- A certified statement of worldwide assets and liabilities;
- A certificate and schedule of all financial accounts held during the period of the fraud;
- A certificate and schedule of all financial cards held during the period of the fraud; and
- A Certificate of Full Disclosure.
HMRC retains the right to criminally investigate any false declarations made in these Formal Disclosure documents.
- Rejection or No Response: If the customer rejects the offer or makes no response, HMRC has the option of starting a criminal investigation by referring the case to the Fraud Investigation Service (Crime), though in most cases HMRC will pursue a civil investigation on the basis of non-cooperation.
Incentive for Cooperation
The customer's further cooperation after the Outline Disclosure is induced by the prospect of maximising reductions in penalties.
Citation sources
The detail of our evidence/concerns will not be disclosed to the taxpayer at the outset, as the procedure is to allow the taxpayer the opportunity to make a full disclosure under the Contractual Disclosure Facility (CDF) (see FCIM103050). We no longer need to indicate at the outset the tax regime or regimes under which our concerns lie.
COP9 is HMRC’s main tool for investigating cases of suspected tax fraud using civil procedures. At certain points it also opens the possibility of a criminal investigation. This would be carried out by (not using COP9). COP9 applies once it has been issued to the taxpayer, with an offer of a contractual arrangement and a covering letter. Once COP9 has been the taxpayer they will have 60 days from the day from the day they receive it to choose one of three options. They can either: fully cooperat
The letter offering the Contractual Disclosure Facility (CDF) must not indicate the reasons why the case has been registered for investigation. If advisers query the policy, you must refer them to the Code of Practice 9 which says: ‘We will not usually tell you what our suspicions are; it is for you to decide to make a disclosure to us’. This is because: An investigation under COP9 must give the customer an opportunity to make a full and complete disclosure of any irregularities and minimise any
COP9 is HMRC’s main tool for investigating cases of suspected tax fraud using civil procedures. At certain points it also opens the possibility of a criminal investigation. This would be carried out by The Fraud Investigation Service (Crime), not using COP9 procedure. COP9 applies once it has been issued to the customer, together with an offer of a contractual arrangement and a covering letter. Once COP9 has been sent to the customer they will have 60 days to choose one of two options. They can
As part of a valid Contractual Disclosure Facility (CDF) the customer agrees to submit a Formal Disclosure. The Formal Disclosure consists of the following: Certified statement of worldwide assets and liabilities Certificate and schedule of all financial accounts held during the period of the fraud Certificate and schedule of all financial cards heldduring the period of the fraud Certificate of Full Disclosure. Each of the above documents must be signed and dated by the customer. You cannot acce
OFFER BY HMRC UNDER THE CONTRACTUAL DISCLOSURE FACILITY TO [NAME], [DOB] OF [FULL ADDRESS] DATED [date] This offer is made to the above named individual only and is made strictly on the basis of the terms and conditions set out in the current edition of HMRC Code of Practice 9. Most importantly, this offer is made in the expectation that at all stages throughout the CDF process your disclosures to HMRC will be full, open and honest and you will provide accurate, timely and complete information t
At the core of HMRC’s compliance strategy is the wish to encourage voluntary compliance. Currently most voluntary disclosures will either be handled under the Contractual Disclosure facility (CDF) or through one of the publicised offshore disclosure facilities, such as the Liechtenstein Disclosure Facility (LDF). It will be rare to encounter a genuinely unprompted disclosure which does not fulfil the criteria for either CDF or an offshore disclosure facility. It is extremely important to ensure
HMRC’s offer of a contract and the customer’s acceptance are what create a valid contract and give the customer the assurance that they will not be criminally investigated for what they disclose in their Outline Disclosure. A valid Contractual Disclosure Facility (CDF) agreement can only be made by the customer accepting the standard offer that has been made. You cannot make an offer on any other terms. The opening letter includes a standard acceptance letter, which is available in SEES. This mu