Category: Tax investigations and HMRC powers · Reviewed by the Apex broking team · Last reviewed 2026-08-20
Category: Tax investigations and HMRC powers Also known as: COP8, Code of Practice 8 investigation, FIS civil investigation Related concepts: COP9 and the Contractual Disclosure Facility, Schedule 36 information notice
Code of Practice 8 is one of two published codes of practice under which HMRC’s Fraud Investigation Service conducts civil investigations. HMRC issues COP8 where it suspects that a serious loss of tax has occurred — often through complex structures, avoidance arrangements or offshore matters — but is not, at that stage, alleging fraud. The code explains how the investigation will be conducted, what HMRC expects of the taxpayer, and what the taxpayer can expect of HMRC.
The distinction between the two codes is the allegation being made. Under Code of Practice 9, HMRC suspects deliberate fraud and offers the Contractual Disclosure Facility; under COP8 it does not. A COP8 case is a civil investigation into a suspected serious tax loss where honesty is not, at the outset, in question. That position is not fixed: if evidence of fraud emerges during a COP8 investigation, HMRC can move the case to COP9 or, in some circumstances, consider a criminal investigation. Equally, a COP8 case may conclude with no additional tax found due.
There is no standard shape. COP8 investigations are conducted by specialist officers, commonly run for years rather than months, and typically involve detailed requests for documents and explanations, meetings, and analysis of structures spanning several tax years and several taxes. HMRC may use its formal information powers under Schedule 36 Finance Act 2008 where information is not provided voluntarily, and may make assessments — including discovery assessments for earlier years — where it concludes tax has been lost.
Because the subject matter is by definition serious and often technically complex, professional representation in a COP8 case is sustained work: reconstructing transactions, responding to successive rounds of enquiry, negotiating the scope of information requests and testing HMRC’s technical analysis. Fees reflect the duration and depth of the exercise rather than any single event, which is why COP8 cases are among the most expensive investigations to defend even where the outcome is favourable.
The professional fees of responding to HMRC interventions are the subject of tax fee protection insurance. Wordings differ on Fraud Investigation Service work: fee protection policies typically exclude matters involving dishonesty or fraud, and cover for a COP8 case — where fraud is not alleged but the investigation is conducted by the Fraud Investigation Service — depends on the individual policy wording, including how and when any exclusion is applied. The policy documents, not the label on the investigation, determine the position.
A COP8 letter signals that HMRC regards the suspected tax loss as serious and has assigned it to its specialist investigation arm. Understanding what the code does and does not allege — and how the case could escalate — frames both the professional response and the question of who bears the cost of it.
This entry is part of the Apex Insurance Wiki. Last reviewed 2026-08-20. Next review: 2027-02-20.
Apex Insurance Brokers Limited. Authorised and regulated by the Financial Conduct Authority, FRN 724952. Registered in England and Wales, Companies House 07014570. This entry provides general information about UK insurance concepts and is not regulated advice. Consult your insurance broker on your specific position.
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