Facing a Code of Practice 8 (COP8) Investigation?

Code of Practice 8 is the procedure HMRC's Fraud Investigation Service uses for serious cases of suspected tax avoidance or complex irregularities where deliberate fraud is not, at the outset, suspected. It sits between a routine compliance check and the fraud-focused Code of Practice 9 process.

A COP8 letter explains that HMRC is investigating your tax affairs under this code, and typically outlines the general area of concern, such as a tax avoidance scheme, offshore arrangement or complex structuring. It does not use the Contractual Disclosure Facility that COP9 relies on.

Because COP8 covers a wide range of situations, from aggressive scheme use to genuinely uncertain technical positions, the letter's precise wording and the areas it identifies matter a great deal in working out how serious HMRC currently considers the case.

COP8 cases are commonly triggered by HMRC identifying involvement in a tax avoidance scheme, unusual offshore structures, complex group or trust arrangements, or a pattern of transactions that appears designed to reduce tax in a way HMRC wants formally examined.

It can also arise where HMRC has information suggesting significant undeclared tax exposure but the facts are not yet clear enough to justify a fraud-based COP9 approach. In some cases, HMRC opens COP8 following intelligence from disclosure facilities, data exchange with other tax authorities, or referrals from other parts of HMRC.

A COP8 letter does not confirm HMRC's final view of your conduct. It reflects HMRC's assessment at the point of opening the case, and that assessment can change, in either direction, as the investigation proceeds.

Within a COP8 investigation, HMRC generally uses the same statutory information powers as in other checks, including Schedule 36 notices, and can request documents and information reasonably needed to establish the facts, which can extend to personal bank statements where relevant to the tax position under review.

You retain the same underlying rights as in any compliance check: information requests must be reasonably required, and certain Schedule 36 notices can be appealed within 30 days if not tribunal-approved. Refusing a valid, reasonable request without formally challenging it is generally unwise given the seriousness HMRC already attaches to a COP8 case.

Where HMRC proposes a meeting, careful preparation matters more in a COP8 case than in a routine check, since statements made can shape how HMRC views your conduct and whether the case might later move towards a fraud classification.

COP8 investigations commonly run for many months, and complex cases involving multiple entities, jurisdictions or years can extend well beyond a year. There is no statutory maximum length, so progress depends on the complexity of the facts and the pace of evidence-gathering on both sides.

A COP8 case can end with HMRC accepting your explanation and closing the review with no adjustment, with an agreed settlement covering additional tax, interest and any penalty, or with formal assessments that you can choose to accept or appeal.

In some cases, evidence uncovered during a COP8 investigation leads HMRC to consider the conduct deliberate, at which point the case can be escalated towards a Code of Practice 9 approach, with different disclosure mechanics and consequences.

Penalties in a COP8 case follow the same behaviour-based framework used elsewhere in HMRC's compliance work: broadly, careless errors sit at the lower end of the penalty range, while deliberate, and especially deliberate and concealed, conduct sits at the higher end.

Whether a disclosure is prompted or unprompted also affects the available reduction, as does the quality of cooperation: telling HMRC fully, helping with the investigation, and giving reasonable access to records can all support a lower penalty within whatever range applies to the behaviour found.

Because a COP8 case often involves genuinely arguable technical positions, part of the investigation may focus on whether an error exists at all before any penalty question arises. Do not accept a behaviour label from HMRC without checking whether the underlying facts support it.

Treating COP8 correspondence as routine and responding without full preparation is a common and costly mistake, since inconsistent or incomplete answers can shift HMRC's perception of your conduct from avoidance towards deliberate wrongdoing.

Other frequent errors include failing to disclose related entities or overseas elements not explicitly asked about, giving verbal explanations in meetings that are not later supported by documentation, and delaying specialist advice until after a difficult meeting has already taken place.

Assuming that COP8 is 'less serious' than COP9 and therefore does not need the same rigour is also a mistake. While the starting point differs, the eventual financial and reputational consequences of a poorly handled COP8 case can still be significant.

Consider a landlord based in Morden with a portfolio held through a mix of personal ownership and a small property company, who receives a COP8 letter referencing an offshore mortgage arrangement used to finance one property. HMRC states it is investigating the tax treatment of the arrangement under Code of Practice 8.

The landlord's advisers first map every property, entity and financing arrangement connected to the portfolio, not just the one HMRC named, since incomplete disclosure of related structures tends to prolong and worsen these cases. They then review whether the offshore financing produced any tax advantage that was correctly or incorrectly reported.

Where a genuine technical uncertainty exists about how interest relief was claimed, the response sets out the position taken, the reasoning behind it, and the evidence supporting it, rather than assuming any adjustment automatically implies deliberate conduct. This measured approach keeps the case focused on the facts rather than allowing it to escalate unnecessarily.