CH23560 | Information & Inspection Powers: Information Notices: Taxpayer Notice: Meaning of 'reason to suspect'
From HM Revenue & Customs · Compliance Handbook
‘Reason to suspect’ means that there are facts which, either alone or taken together with others, lead you to think that the person
may have been under-assessed to or may have underpaid tax or
may have claimed or been given excessive tax relief.
These facts will need to be disclosed
Having a reason to suspect that tax may have been under-assessed, and so on, does not mean that you already have to be in a position to make an assessment. You will use the information power to enable you to decide what, if any, assessment must be made.
On the other hand ‘reason to suspect’ does not allow you to make speculative enquiries, seeking information merely in the hope that something relevant will crop up. You must be able to identify specific risks.
FA08/SCH36/PARA21 (6)