What Is COP9?

HMRC Code of Practice 9 (COP9) is a notice issued when HMRC suspects tax fraud or deliberate misrepresentation in your tax affairs.

Unlike COP8, which deals with civil investigations for tax avoidance or irregularities, COP9 is serious — HMRC believes there may have been intentional wrongdoing.

The good news: HMRC offers the Contractual Disclosure Facility (CDF), which allows you to admit to fraud voluntarily. By disclosing fully and honestly, you can avoid criminal prosecution while settling any unpaid tax, interest, and penalties.

Receiving a COP9 letter can feel intimidating, but it doesn’t automatically mean you will be prosecuted. Your response determines the outcome.

COP9 vs COP8 — Understanding the Difference

Many people confuse COP8 and COP9. Here’s the difference in simple terms:

COP8 = Civil investigation for suspected tax avoidance or irregularities, such as missed returns, complex schemes, or undeclared offshore income.

COP9 = Investigation for suspected tax fraud, where HMRC believes there has been deliberate misrepresentation.

The key distinction: COP9 comes with the CDF, offering a legal pathway to avoid prosecution if you disclose everything fully.

Remember: a COP8 can escalate to COP9 if HMRC finds evidence of deliberate dishonesty.

What Triggers a COP9 Investigation?

COP9 is usually triggered when HMRC suspects intentional wrongdoing. Common situations include:

• Fraudulent or falsified tax returns
• Deliberate underreporting of income or overclaiming deductions
• Use of offshore accounts or assets to conceal income
• Deliberate failure to submit tax returns or big gaps in filings
• False statements about assets, business expenses, or company structures
• Complex schemes designed to mislead HMRC
• Even missing a few years of tax returns can catch HMRC’s attention. Large gaps in filings, undeclared income, or unfiled tax returns are treated very seriously, especially when combined with other red flags.

What Happens During a COP9 Investigation?

HMRC will take a very detailed look at your tax affairs, including:

• Reviewing all financial records
• Examining bank accounts, contracts, invoices, and correspondence
• Checking lifestyle versus reported income
• Investigating offshore accounts or hidden assets
• Determining whether actions were deliberate and dishonest

The CDF is key — it allows you to disclose everything voluntarily and negotiate repayment without fear of criminal prosecution.

Failing to cooperate or hiding information can quickly escalate the situation, potentially leading to criminal charges, higher penalties, or even prosecution.

Can COP9 Lead to Criminal Prosecution?

Yes — and this is why COP9 is taken very seriously.

If you do not disclose fully under the CDF, HMRC may treat the case as criminal tax fraud. Potential consequences include:

• Heavy financial penalties
• Repayment of tax plus interest
• Criminal prosecution, fines, or imprisonment

Even relatively small amounts of undeclared income can escalate if HMRC believes there was intent to deceive.

How to Respond If You Receive a COP9 Letter

• Act immediately. Ignoring a COP9 letter only increases risk.
• Engage our specialist adviser with experience in COP9 and tax fraud investigations.
• Do not contact HMRC directly until advised.
• Gather all records, including undeclared income, unfiled returns, offshore accounts, and correspondence.
• Decide on entering the CDF — full disclosure is essential.

Our specialist will guide you, structure your disclosure, communicate with HMRC, and help negotiate penalties while protecting you from prosecution.

What is the Contractual Disclosure Facility (CDF)?

he CDF is a voluntary disclosure program. By fully revealing any underpaid tax or concealed income, HMRC allows you to:

• Avoid criminal prosecution
• Negotiate repayment, penalties, and interest
• End the investigation on civil terms
• Full honesty is essential — partial or incomplete disclosure will not protect you.

How Long Does a COP9 Investigation Take?

COP9 investigations are typically longer and more complex than COP8:

• Most last 12–36 months, depending on case complexity
• Length increases with multiple parties, offshore accounts, or historical gaps in filing
• Responsiveness, transparency, and full disclosure can significantly speed up the process