COP9 and COP8: Code of Practice 9 and Code of Practice 8 Tax Investigations

COP9 and COP8 are HMRC procedures used by its Fraud Investigation Service (FIS) for civil investigations involving suspected tax fraud or significant tax risks. COP9 (Code of Practice 9) is used where HMRC suspects tax fraud and incorporates the Contractual Disclosure Facility (CDF). COP8 (Code of Practice 8) is used where HMRC considers there may be a significant loss of tax and the COP9/CDF procedure is not being used.

About the author

This article was prepared by Amit Puri, Founder & Managing Director of Pure Tax Investigations. Amit was a technically qualified Inspector of Taxes with HM Revenue & Customs from 2004 to 2015 and has over 20 years’ experience focused on tax investigations, including HMRC Code of Practice 8, Code of Practice 9 and Contractual Disclosure Facility investigation cases.

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Most fiscal events include the standard promises of more tax investigative resources at HMRC, with a push for directorates that pursue and challenged large scale avoidance arrangement and fraudulent activities as well as debt management. However, HMRC’s staff numbers don’t tend to increase in real terms, because staff are often recycled from defunct teams.

Last year we wrote about HMRC being due some 5,500 new investigative officers as promised in the preceding Budgets and the June Spending Review. We believe the general public expects HMRC to “do more, with more” however, it always seems the chains have not come off in the case of HMRC’s most aggressive civil tax investigations. HMRC’s Fraud Investigation Service (FIS) conducts these specialist civil investigations, where large amounts of tax are believed to be at risk and/or suspicions of tax fraud are alleged at the outset.

Despite an impressive responsibility, FIS staff numbers have stayed stubbornly close to 5,000 for some years, across the country. Regrettably, anecdotal evidence shows that the public is not afraid of FIS civil investigations and is seldom aware that a person has been subject to one—so the low number of investigations has a poor deterrence effect.

That said, during the 2025/26 year, FIS delivered £2,092 million (down from £2,430 million) in revenue for the Exchequer as a result of our Civil Investigations alone.

In a response to a recent Freedom of Information Act request, HMRC confirmed that it began over 8,100 and closed over 8,300 other Civil Investigations utilising a range of interventions that are not available to other areas of HMRC’s Customer Compliance Group when they undertake compliance checks. COP8 and COP9 are distinct from ordinary HMRC compliance checks.

Some of those various investigation types use other frameworks and statutory powers. This includes, for example:

investigations into organised labour fraud using powers including those granted under the Finance Act and Taxes Management Act, identifying fraudulent labour supply chains where taxes in relation to the supply are suppressed or evaded;
investigations into Missing Trader Intra-Community (MTIC) fraud using Finance Act powers, challenging fraudulent supply chains aimed at evading payment of VAT;
civil recovery work using Proceeds of Crime Act 2002 powers, for example the seizure, detention and forfeiture of cash or assets which represent the proceeds of crime;
high-value securities work, for example using VAT Act powers, to require payment of security from companies where there is a risk of phoenixism or failure to pay taxes due to HMRC (e.g. VAT, income tax, or environmental taxes);
our mobile enforcement teams detecting, seizing and securing illicit oils, tobacco and alcohol goods using Customs and Excise Management Act (CEMA) powers;
interventions under the Money Laundering Regulations.

What makes these FIS investigations different to routine compliance checks?

Fraud Investigation Service’s civil investigations are a lot more time intensive and resource hungry. FIS investigators typically manage no more than 10 at any time whereas other front-line HMRC officers (for example, in ‘Wealthy and Mid-sized Business Compliance’ and ‘Small Business & Individuals’) have a much higher number of cases (30 to 40) simultaneously.

HMRC is seeking a financial recovery here, of taxes, late payment interest, and typically large penalties, for failing to submit correct tax returns or failing to notify HMRC that taxes were payable. Allegations of having acted deliberately or dishonestly are typical, with HMRC seeking to publicly name and shame people too.

What is tax fraud?

HMRC define fraud as any deliberate omission, concealment or misinterpretation of information, or the false or deceptive presentation of information or circumstances in order to gain a tax advantage.

Tax fraud covers a wide range of illegal activity, including:

deliberately submitting false tax returns
falsely claiming repayments or reliefs
hiding income, gains or wealth offshore
smuggling taxable goods

Most of HMRC’s work to tackle tax fraud makes use of its civil powers. These allow HMRC to get hold of the information it needs to identify and collect unpaid tax, while imposing financial penalties on those responsible (up to 200 percent of the tax due in some cases).

So, more time commitment, more attention and greater experience is required from tax investigation specialists supporting their clients with these types of investigation.

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Which tax investigations does Fraud Investigation Service carry out?

Code of Practice 9

Read our detailed guide to [COP9 – Code of Practice 9 tax investigations]. A COP 9 is HMRC’s civil investigation procedure for selected cases where HMRC suspects tax fraud. HMRC offers the Contractual Disclosure Facility (CDF), giving the taxpayer 60 days to accept or reject the offer. If the taxpayer accepts the CDF and makes a complete, accurate, open and honest disclosure of the relevant deliberate behaviour, HMRC undertakes not to commence a criminal investigation into that disclosed behaviour, subject to the terms of the CDF.

Taxpayers must disclose the background and reasons for their deliberate actions, compute the additional income, profits, gains, taxes, and late payment interest and penalties—all at their own cost. HMRC expects taxpayers to commission comprehensive disclosure reports—usually prepared by suitably experienced tax investigations specialists. In return, lengthy, in-depth, and intrusive investigations by HMRC are avoided, which can otherwise run on for many years.

What is the Contractual Disclosure Facility (CDF)?

If you accept HMRC’s CDF process offer, you must:

Admit involvement in tax fraud within 60 days.
Provide an outline disclosure of all deliberate tax irregularities. This should be high-level in terms of the dates of the frauds, the amounts involved, other people involved, and the matters concerned. HMRC will compare this information against that which they hold already leading to their suspicion.
One the outline disclosure is submitted and accepted by HMRC, you should meet HMRC to discuss it, the records available now, and commission a detailed disclosure report (at your own cost) explaining what happened, when, why, and with whom — supported by evidence and figures.

Remember, rejecting or ignoring the CDF offer can result in HMRC escalating the case to criminal proceedings if they decide not to continue with the COP 9 investigation. The Contractual Disclosure Facility offer and outline disclosure creates that contract.

See HMRC’s published booklet at: Code of Practice 9: where HMRC suspects fraud (COP9) – GOV.UK

What happens when HMRC issues a COP9?

Then perhaps:

HMRC issues the COP9/CDF offer.
The taxpayer has 60 days to accept or reject the CDF.
If accepted, an Outline Disclosure is required.
The taxpayer then proceeds with the detailed disclosure process.
HMRC assesses the tax, interest and penalties arising from the disclosed irregularities.
HMRC’s undertaking regarding criminal investigation is subject to the CDF terms.

HMRC’s current guidance is very clear about these stages.

Code of Practice 8

See our detailed guide to [COP8 – Code of Practice 8 tax investigations]. A COP 8 is HMRC’s civil investigation procedure for cases where HMRC believes there may be a significant loss of tax. It can apply to individuals, partnerships, LLPs, companies and trusts and can cover different taxes and tax regimes. COP8 does not use the Contractual Disclosure Facility associated with COP9. It’s not unusual for these to be used against marketed avoidance schemes or arrangements and bespoke tax planning, where HMRC is likely to have made a discovery about large historic tax losses.

COP8 does not itself mean that HMRC has alleged tax fraud. However, issues concerning deliberate behaviour or suspected fraud can arise during a COP8 investigation, and HMRC’s investigation approach can change depending on what the evidence reveals.

The investigators are well prepared to argue they have identified new information and culpability— also triggering penalties. There is little possibility of dissuading them in favour of a COP9-style disclosure report and also typically some span years due to their in-depth nature.

Can a COP8 investigation become a COP9 investigation?

A COP8 investigation does not automatically become a COP9 investigation. However, if the facts uncovered during an investigation lead HMRC to suspect serious tax fraud, the investigation may be dealt with under COP9 or another appropriate procedure. The precise approach depends on the facts and HMRC’s assessment of the case.

COP9 and COP8 similarities. COP 9 and COP 8 have the following in common:

Feature	COP8	COP9
HMRC Fraud Investigation Service	✓	✓
Civil investigation	✓	✓
Potentially multiple tax years	✓	✓
Potential third-party information gathering	✓	✓
Significant HMRC information-gathering powers	✓	✓
Potential tax, interest and penalties	✓	✓
Specialist investigation rather than routine compliance check	✓	✓
Not routine compliance checks	✓	✓

Typically the investigators consider and assess several prior years or accounting periods, by arguing they have made a “discovery.” I.e. they discovered something they could not have known previously from the tax returns submitted (if they were) alone.

FIS investigators tend to identify and challenge “careless” and “deliberate” actions which support their reasons for looking at older periods, and so habitually go beyond the normal four years assessing-limit.

What is the difference between COP8 and COP9?

HMRC COP9 and COP8 investigations: latest statistics

HMRC’s latest published 2025/26 statistics show that 296 COP9 investigations were opened and 724 were closed, while 191 COP8 investigations were opened and 380 were closed.

Overall in fiscal year 2025/26:

Almost 500 new cases were opened.
37 more cases were opened altogether.
248 more cases were concluded altogether; so HMRC have been busy.
Total yield / revenues secured remained flat at £144 million.
The number of COP9 tax fraud cases opened remained flat at 296 (previously 306).
Much more COP8 cases were opened, at 191, up from 144 previously.

Notably, there was the continuing trend of more cases being concluded. This demonstrates HMRC’s focus being on settling older cases. This is welcomed, because HMRC is regularly criticised by tax practitioners for not settling enquiries and investigations sooner.

However, 2023/24 was an anomaly year, but not because there were more larger yielding cases settled. During that year, an exponentially long-running, and exponentially large COP9 tax fraud case was concluded, which has skewed the statistics for that reporting year.

COP8 closures increased from 265 in 2024/25 to 380 in 2025/26. These figures provide useful context when considering HMRC’s current workload, although case closures and yield in a particular year do not necessarily relate to investigations opened in that same year. The average yield in those cases was £202,000 compared to the £182,000 previously.

In COP9 cases, the average yield was £93,000, whereas previously it was £164,000. That’s a significant reduction.

The average penalties charged across COP9 and COP8 cases during 2025/26 was strangely similar, at £18,000 per case concluded. This is surprising, because COP9 cases are about tax fraud, whereas COP8 cases focus on tax planning and avoidance schemes i.e. where a client might not be culpable for the tax losses therefore penalties should in theory be lower.

As an aside, we understand tax practitioners consider there is a clear case for more such investigations being done, given the tax yields and deterrence effect that would secure, but HMRC seem to disagree. Our experience suggests that the financial and non-financial consequences of FIS investigations are not always fully appreciated before an investigation begins.

The key difference is that COP9 is HMRC’s civil procedure for selected cases where it suspects tax fraud and offers the Contractual Disclosure Facility, whereas COP8 is used where HMRC considers there may be a significant loss of tax and the COP9/CDF procedure is not being used.

HMRC’s own internal guidance expressly distinguishes the two in essentially this way.

A COP9 investigation is likely to be particularly significant for a taxpayer because HMRC is expressly investigating suspected tax fraud and the CDF procedure involves important contractual decisions and strict time limits.

But it’s possible to secure immunity from a criminal tax investigation and potential prosecution by admitting tax fraud and accepting HMRC’s offer of commissioning a detailed disclosure report —a taxpayer may explain what happened, when, why, how, with whom, plus present evidence and comprehensive figures.

COP8 investigations can initially appear less serious than COP9 because HMRC does not necessarily allege tax fraud at the outset. However, a COP8 investigation can involve significant tax risks, multiple years, third-party information and detailed scrutiny of transactions and arrangements.

These investigations might appear similar to routine inquiries at first, but as the cases progress, clients often realise that the FIS investigators are looking at old transactions and are ready to use formal Information Notices to gather facts and evidence from them and third parties.

In a COP9 investigation, the client and their adviser should take control of the case by securing the disclosure process for tax frauds and other irregularities, agreeing to investigate all matters in detail themselves. This includes approaching third-parties for information and records, for example, suppliers, customers, banks. They should manage HMRC’s expectations by providing material progress updates as well as timeframes for disclosure report submissions, and making timely payments on account.

In a COP8, the client is the subject of an investigation, so HMRC is asking questions and verifying information to test and confirm their tax risks. A COP8 is comparatively more difficult to manage due to the uncertainties including HMRC’s willingness to approach third parties directly causing clients distress e.g., reputational damage.

	COP9 – Code of Practice 9	COP8 – Code of Practice 8
HMRC procedure	Civil investigation	Civil investigation
HMRC team	Fraud Investigation Service (FIS)	Fraud Investigation Service (FIS)
Main purpose	Selected cases where HMRC suspects tax fraud	Cases where HMRC considers there may be a significant loss of tax and COP9/CDF is not being used
Tax fraud suspected at outset?	Yes	Not necessarily
Contractual Disclosure Facility (CDF)	Yes	No
Criminal investigation protection	CDF can provide a contractual commitment not to pursue a criminal investigation concerning disclosed deliberate behaviour, subject to its terms	No equivalent CDF protection
Typical issues	Deliberate tax losses / suspected fraud	Significant tax risks, including certain avoidance/planning cases
Investigation scope	Potentially multiple years and tax regimes	Potentially multiple years and tax regimes
Specialist advice	Appropriate given the procedure and time limits	Appropriate given the potential scope and powers

Last reviewed: September 2026

Statistics: HMRC financial year 2025/26