IHTM40143 - Changes after the issue of the clearance certificate: fraud or failure to disclose material facts
The issue of a clearance certificate does not stop you from collecting tax if there has been a failure to disclose material facts or fraud.
If you receive information that suggests the account was materially incorrect it should be referred to Risk. If they consider it worth pursuit they will refer the case to Compliance to consider whether the new information justifies opening a new enquiry.
Examples of situations where there may have been a failure to disclose material facts include