Code of Practice 8 is the less famous cousin of COP9, but for many taxpayers it is the more relevant route. Where COP9 is reserved for cases in which HMRC suspects deliberate behaviour, COP8 covers complex civil investigations that fall short of that threshold but where the agency considers the matter sufficiently serious to be handled by its Fraud Investigation Service rather than a routine enquiry team.
What COP8 is
COP8 is HMRC's published code for civil investigations of suspected serious fraud or other complex matters where deliberate behaviour is not (yet) alleged. Cases come into COP8 by a number of routes: marketed avoidance schemes that HMRC considers abusive, large or complex offshore arrangements, intricate corporate restructurings, or single transactions of high value where the technical analysis is contested.
The critical difference from COP9
The key distinguishing feature is the absence of an admission or allegation of deliberate behaviour. There is no Contractual Disclosure Facility, no 60-day acceptance window, and no automatic criminal protection — because no deliberate conduct is being assumed. The investigation proceeds as a civil enquiry, albeit one conducted by experienced fraud investigators rather than general compliance staff.
What that means in practice
A COP8 investigation typically involves:
- Detailed information requests under Schedule 36 Finance Act 2008, often broader than a routine enquiry.
- Third-party notices to banks, professional advisers, or counterparties.
- Meetings with HMRC where the taxpayer (with their adviser) is asked to explain transactions, decisions, and the rationale behind a particular tax position.
- A potentially lengthy timeline — COP8 cases regularly run for two to four years from opening to closure.
The escalation risk
The most important strategic point about COP8 is that it can escalate. If during the investigation HMRC comes to believe that deliberate behaviour was involved, the case can be reclassified into COP9 (or referred for criminal prosecution). This is why early, well-managed engagement matters — a defensive or evasive response to legitimate Schedule 36 notices can itself raise HMRC's suspicions and tip the case in a worse direction.
Penalty exposure
Without deliberate behaviour, penalties under Schedule 24 Finance Act 2007 are limited to the careless or non-careless bands. Careless penalties range from 0% to 30% of the tax (depending on whether the disclosure was prompted and how cooperative the taxpayer is). Many COP8 cases conclude with a "no penalty" outcome if the taxpayer can show reasonable care was taken, even where additional tax is due.
Settlement and closure
COP8 cases typically conclude with a closure notice under TMA 1970 s.28A (for income/capital gains tax) or the equivalent provision for the relevant tax. The notice records HMRC's amendments and the resulting tax. Closure can be agreed by negotiation, or HMRC can issue a unilateral closure notice which the taxpayer then appeals to the First-Tier Tax Tribunal within 30 days. ADR is available throughout.
Working with HMRC's Fraud Investigation Service
FIS investigators are more experienced and more thorough than typical local compliance teams. They expect:
- Clear, structured responses to information requests.
- Documentation that traces transactions end-to-end, not just summary figures.
- Honest acknowledgement of uncertainty where it exists, rather than overconfident assertion.
- A willingness to meet, present, and answer follow-up questions.
Where the taxpayer engages an adviser at the outset and presents a coherent case file, FIS investigators are often pragmatic. Where the taxpayer drifts, misses deadlines, or makes inconsistent statements, the case can drag on for years and the penalty exposure grows accordingly.
The role of pre-existing tax planning
Many COP8 cases originate from historical tax planning — arrangements entered into years earlier that HMRC now considers to fail. The defence depends heavily on the contemporaneous documentation: was reasonable professional advice taken at the time, were the facts accurately disclosed to the adviser, were the implementation steps followed? Our tax planning work always emphasises documentary trail because it can become decisive years later. The same applies to corporate transactions: clean board minutes and well-papered structures recorded in annual accounts reduce the friction of any future review.
If you receive a COP8 letter
- Engage a specialist adviser early. COP8 work is not routine tax compliance.
- Preserve all records. Document destruction is itself an offence and any spoliation will be inferred against you.
- Map your historic position. Reconstruct the transactions, the advice taken, and the documents created — this is the foundation of the defence.
- Be honest about weaknesses. Where a position is genuinely difficult to defend, early acknowledgement reduces penalties and shortens timelines.
This article is general information and not advice for any specific COP8 matter. If a COP8 letter has been received, professional advice should be sought immediately. We are happy to provide an initial confidential discussion through our contact page or you can book a call directly with our team.