CH231700 - How to do a compliance check: information powers: rules that apply to all notices: accountants’ working papers: inaccuracies
You should bear in mind that HMRC’s Compliance Accountants are available to give advice on examining working papers. You must seek their advice where you have reason to believe that any papers may contain deliberate inaccuracies. They hold responsibility for the operation of TMA70/S99.
It is a mandatory requirement that any suspicion of fraudulent conduct must be reported to Fraud Investigation Service, this should be done by referring the case to the Evasion Management Team.