Understanding HMRC COP0 investigation and how to respond
If you have received a Code of Practice 9 (COP9) letter from HMRC, you are in the serious position of being suspected of tax fraud.
While the stress of a civil investigation by HMRC is likely, there is a way forward involving specialist advice and a disclosure under HMRC’s Contractual Disclosure Facility (CDF).
Understanding COP9 and the CDF will help you in this process. It’s also important to understand how decisions made at the outset can have long term financial and legal consequences, making early advice from specialists essential.
Tax fraud and the use of COP9 investigations
Tax fraud is any dishonest deliberate behaviour that leads to, or was intended to lead to, a loss of tax i.e. tax evasion. This includes:
- Deliberately paying less tax than is owed
- Deliberately claiming repayments or reliefs that you are not eligible for
- Deliberately withholding or concealing relevant facts
- Providing false or misleading information to HMRC
- Using offshore bank accounts or assets to conceal income or gains
- Using structured arrangements with the intention of evading tax
While tax fraud is a criminal offence, COP9 gives you the opportunity to make a full disclosure using the CDF and to resolve matters without a criminal prosecution. It is your responsibility to disclose all relevant issues to HMRC: HMRC do not provide details of the suspected deliberate behaviour.
Where relevant, the CDF can also be used to voluntarily disclose deliberate behaviour that has led to you paying less tax, following specialist advice and co-ordination with HMRC.
Receiving a COP9 letter and seeking advice
A COP9 letter is usually accompanied by an invitation to enter the CDF Failure to reply within the 60-day deadline will be treated by HMRC as a taxpayer’s denial of any deliberate wrongdoing, following which HMRC will investigate.
An incorrect or incomplete response can significantly worsen your position, both financially and in terms of how the investigation is taken forward by HMRC. So as soon as you receive a COP9 letter from HMRC, you should:
- Immediately seek advice from tax dispute resolution specialist
- Refrain from making admissions or explanations directly to HMRC before being properly advised
- Carefully assess whether HMRC’s allegation of deliberate behaviour is justified
You need to consider not just your personal tax affairs, but the tax affairs of any entities, trusts, etc you have control over. HMRC will not communicate with you or your adviser during the 60-day window , so the onus is on you.
Entering into the CDF
By entering into the CDF, you agree to:
- Admit that deliberate tax irregularities have taken place
- Make a full, complete and accurate disclosure of those irregularities
- Cooperate fully with HMRC’s investigation
- In return, HMRC agree not to pursue a criminal prosecution. However, HMRC may commence a criminal investigation despite offering the CDF where:
- You do not respond to the CDF offer within the 60-day period
- You reject HMRC’s offer of the CDF and do not allay their suspicions of tax fraud
- You make an incomplete or incorrect Outline Disclosure
- You make a false statement or submit false documents You submit false Formal Disclosure documents
- You subsequently withdraw your admission of deliberate behaviour
If HMRC embark upon a criminal investigation then you will need formal legal representation, which is far more costly than dealing with matters under a civil process. This makes it essential to minimise the risk of a criminal prosecution by seeking specialist COP9 and CDF advice.
The five key stages of the COP9 and CDF process
Accepting or rejecting the CDF offer
Accepting the CDF – within the 60-day deadline – involves an explicit admission of deliberate behaviour. This cannot later be withdrawn, again emphasising the need for specialist advice from the outset.
If you reject HMRC’s offer, you should fully explain to HMRC why you do not consider there to be any deliberate tax irregularities in your affairs. Despite such explanations, rejecting the CDF may still result in a COP9 investigation continuing and does not guarantee avoidance of an expensive criminal prosecution.
The Outline Disclosure
the CDF is accepted, an Outline Disclosure must be submitted within the 60-day deadline to accompany the admission of deliberate behaviour. This sets out:
- The nature of the deliberate conduct
- The taxes involved
- The tax periods affected
- The methods used to under‑declare tax
- Who else is involved
If HMRC consider the Outline Disclosure to be complete based on their existing information, they will accept it. It will then form the basis of the scope to be agreed for a detailed report.
Meeting HMRC
Once your Outline Disclosure has been accepted by HMRC, you will typically be invited to a face-to-face Opening Meeting with the HMRC investigator. This formal meeting allows HMRC to ask further questions about the deliberate behaviours disclosed. It also demonstrates your cooperation with the investigation, which is part of the contractual obligations of the CDF.
At the end of the meeting, you will be asked to prepare a comprehensive Disclosure Report based on the agreed scope of work.
Disclosure Report
The report must include:
- Explanations of any tax irregularities and historic behaviour, supported by evidence
- Detailed calculations of any additional liabilities, including tax and late payment interest
This stage is often technically complex, with the added complication that deliberate non-compliance for the past 20 years is assessable by HMRC.
Demonstrating progress to HMRC in preparing the report can reduce any eventual HMRC penalty. This makes it crucial to provide information to your advisers promptly.
HMRC review and settlement
HMRC will review the disclosure, raise follow-up questions and seek to agree a settlement covering: tax, interest and penalties.
- Penalties are often substantial for deliberate irregularities, particularly if there are offshore matters involved. Careful, professionally-guided handling of the disclosure process will ensure penalties are mitigated as much as possible.
Risks associated with COP9 and CDF
COP9 and CDF cases are fundamentally different in risk from routine HMRC enquiries, including:
- Criminal investigation if HMRC believes the disclosure is incomplete, with the associated expense of instructing a lawyer
- Penalties of up to 100% for UK matters and up to 200% for offshore matters
- HMRC assessing tax over a 20-year period
- Permanent damage to credibility with HMRC
- Irreversible admissions of deliberate behaviour
A tax adviser with expertise in COP9 and CDF can help to address those risks in ways that many general accountants cannot, by:
Rathetax adviser with expertise in COP9 and CDF can help to address those risks in ways that many general accountants cannot, by:
- Assessing whether HMRC’s allegation of deliberate behaviour is sustainable
- Advising on whether accepting the CDF is appropriate
- Controlling the scope and wordking of disclosures
- Managing HMRC correspondance and meetings
- Minimsing peanalties withi HMRC’s framework
- Helping to manage the risk of escilation to criminal investigation
How BKL can help
We regularly advise individuals facing HMRC COP9 investigations and Contractual Disclosure Facility disclosures, including cases that involve:
- Offshore income and overseas assets
- Long-running historic tax issues
- Complex structures and trust arrangements
- Disputed allegations of deliberate behaviour
BKL’s Tax Risk & Dispute Resolution team combine Big 4 and Top 10 accounting firm experience in running COP9 cases with a more personalised senior level of client service. We provide clear, strategic advice from the outset and manage the entire COP9 process, ensuring disclosures are handled carefully, accurately and professionally.
If you have received a COP9 letter from HMRC or are concerned about potential deliberate tax issues, early specialist advice is essential.
To discuss your situation in confidence, please get in touch with your usual BKL contact or Jessica McLellan using the form below.
Contact Jess
Frequently asked questions: HMRC COP9 Investigations and the Contractual Disclosure Facility
What does a COP9 letter from HMRC actually mean in practice?
A COP9 letter means HMRC suspect deliberate tax evasion, not an innocent mistake.
It signals that your case is being handled by HMRC’s Fraud Investigation Service and is treated as a serious matter. You are being offered the opportunity to disclose irregularities through the Contractual Disclosure Facility (CDF) and resolve it civilly.
In practical terms, this is a high-risk situation where your response will shape the outcome: financially and legally. Decisions made early on can determine whether the matter stays civil or escalates further, causing greater expense.
How serious is a COP9 investigation compared to a normal HMRC enquiry?
A COP9 investigation is HMRC’s most serious civil investigation process.
Unlike standard compliance checks, HMRC start from the position that behaviour was deliberate, not careless or accidental. This allows them to apply stronger powers, longer time limits and higher penalties.
For example, HMRC can assess up to 20 years of tax history, and penalties can reach 100% (UK) or 200% (offshore). This fundamentally changes both the level of scrutiny and the potential financial exposure.
What should I do immediately after receiving a COP9 letter?
The most important step is to seek specialist tax dispute advice before responding to HMRC.
You have 60 days to decide whether to accept the CDF and submit an Outline Disclosure, and HMRC will not clarify their concerns during this period.
Responding too quickly, or without fully reviewing your affairs, can seriously damage your position. A structured review of all relevant entities, income sources, and historic behaviour is essential before making any formal response.
Should I accept the Contractual Disclosure Facility (CDF) offer?
You should only accept the CDF if you have deliberate tax irregularities to disclose.
Accepting the CDF requires a formal admission of deliberate behaviour, which cannot later be withdrawn. In return HMRC agrees not to pursue criminal prosecution, provided your disclosure is full and accurate.
If you reject the CDF, HMRC may still investigate and could escalate matters. The right decision depends on a careful assessment of your facts, risks, and available evidence.
What happens if I miss the 60-day deadline or ignore the CDF?
If you miss the deadline, HMRC will treat this as a denial of deliberate behaviour and proceed with their own investigation. This removes the protections offered by the CDF and increases the likelihood of a more adversarial or potentially criminal route.
Even partial engagement or late responses can weaken your position. The deadline is strict, and managing it properly is critical to controlling risk.
Can HMRC still start a criminal investigation after offering the CDF?
Yes, HMRC can still pursue a criminal investigation if the CDF conditions are not properly met.
This can happen if your disclosure is incomplete, inaccurate, misleading, or if you fail to cooperate fully. It can also occur if you reject the CDF without addressing HMRC’s concerns.
The protection from prosecution only applies to fully disclosed deliberate behaviour. This makes accuracy and completeness essential throughout the process.
What needs to be included in an Outline Disclosure?
An Outline Disclosure is a summary of all deliberate tax irregularities. It should clearly set out the behaviour involved, taxes affected, relevant time periods, methods used, and any associated parties.
Although it is not the full report, HMRC uses it to decide whether your disclosure is credible and complete. It effectively defines the scope of the entire investigation, so getting it right at this stage is critical.
How long can HMRC go back in a COP9 case?
HMRC can usually assess up to 20 years of tax history in cases involving deliberate behaviour.
This extended time limit reflects the seriousness of suspected fraud and can significantly increase the total liability, especially where issues are long-running or involve multiple entities or offshore assets.
This is one reason why early, organised evidence-gathering is essential to manage the process and mitigate penalties.
What are the financial consequences of a COP9 settlement?
A COP9 settlement typically includes tax owed, interest, and penalties.
Penalties can be severe, depending on the behaviour and level of cooperation: up to 100% of the tax for UK matters and up to 200% for offshore matters.
The quality and timing of your disclosure play a key role in reducing penalties. Demonstrating openness, accuracy, and cooperation can significantly influence the final outcome.
Is it a misconception that COP9 automatically leads to criminal prosecution?
Yes, COP9 is specifically designed to avoid criminal prosecution if handled correctly.
A common misunderstanding is that receiving a COP9 letter means prosecution is inevitable. In fact, the CDF offers a route to resolve matters civilly.
However, this protection depends entirely on making a full, accurate, and honest disclosure. If HMRC later finds omissions or inconsistencies, that protection can be removed.
Do I need a specialist adviser, or can my usual accountant handle a COP9 case?
COP9 cases typically require specialist tax dispute expertise, not routine compliance support. These investigations involve legal risk, complex disclosure requirements, and strategic interaction with HMRC’s Fraud Investigation Service.
A specialist adviser helps control the narrative, manage HMRC engagement and minimise penalties. If a case shows signs of moving towards criminal investigation, separate legal advice may be required, increasing costs and risks.
Can I approach HMRC voluntarily under COP9 if I haven’t been contacted yet?
Yes, you can make a voluntary disclosure of deliberate tax irregularities using the COP9/CDF process. This involves approaching HMRC proactively and requesting entry into the facility, usually with specialist support.
Voluntary disclosure can demonstrate cooperation and may reduce penalties compared to waiting for HMRC to initiate contact, particularly where offshore assets, undeclared income, or historic issues are involved.
