HMRC have produced a new factsheet which gives a brief outline of taxpayers' rights when an irregularity is found during a compliance check.
The factsheet will issue in the context of a compliance check having been carried out and notifies the taxpayer that an offense may have been committed and that the taxpayer may be liable to a penalty. It gives a brief outline of the process for raising an assessment to tax and penalties and how to appeal an assessment to tax along with details on how to apply for financial assistance for appeals.
Full details of the factsheet are available here