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Investigation letter · COP8

Code of Practice 8 investigations

For a letter that mentions Code of Practice 8 (COP8). This page quotes HMRC's own code, word for word, with the source and the date it was last checked.

Last reviewed 8 October 2026 · How Tax Letters checks its facts

What HMRC's code says

What GOV.UK calls it
HMRC publishes it on GOV.UK as “Fraud Investigation Service: Code of Practice 8”  [1]
What it is
In its own words: “This Code of Practice explains how the Fraud Investigation Service (FIS) at HM Revenue and Customs (HMRC) carries out civil investigations in certain cases where the Code of Practice 9 is not used.”  [2]
On prosecution
It says: “We will not undertake this investigation with a view to a criminal prosecution but we may take a different approach if we suspect or find evidence of fraud at any time during our investigation. We may then deal with the investigation under Code of Practice 9.”  [2]
On advisers
It says: “You may want to consider appointing a professional adviser to represent you during our investigation. This is a matter for you to decide.”  [2]
On health and personal circumstances
It says: “If there is anything about your health or personal circumstances that may make it difficult for you to deal with this check, please tell the investigating officer.”  [2]
If the letter is also an information notice
HMRC's factsheet CC/FS2 says that if you disagree with an information notice, the notice will tell you what you can appeal against and how.  [3] Information notices and compliance checks.

Tax Letters does not cover these investigations in detail. This page shows what HMRC's own code says, where it says it, and where to find help.

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You can also deal with HMRC directly, free, without any adviser. Free help: TaxAid, which says it helps “people who can’t afford to pay for help”, and Citizens Advice.

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Sources

  1. GOV.UK: Fraud Investigation Service: Code of Practice 8 (checked 8 Oct 2026)
  2. HMRC: Code of Practice 8 (GOV.UK PDF) (checked 8 Oct 2026)
  3. GOV.UK: Information notices, CC/FS2 (checked 7 Oct 2026)