IHTM09362 | How to use third party information: sources of information

From HM Revenue & Customs · Inheritance Tax Manual

You may receive third party information

under our statutory information powers (IHTM32191)
under a Double Taxation Convention (IHTM27161)
in response to an informal request by HMRC
from a named informer
from an anonymous informer
from another HMRC source (for example, where information has been received in connection with a separate enquiry).

You may disclose information obtained under our information powers (IHTM09363) or from a foreign tax authority (IHTM09364) under a Double Taxation Convention under certain circumstances.

But if the information is received informally from a non-statutory source (IHTM09365) then it is essential that you preserve the confidentiality of the third party.