FHDDS26100 | Policy and background: know or have reasonable grounds to suspect: what is meant by ‘know or have reasonable grounds to suspect’
From HM Revenue & Customs · VAT Fulfilment House Due Diligence Scheme
Fulfilment businesses must take steps when they discover that one of their overseas customers has not complied with a UK VAT or customs duty obligation. There is more information about what a fulfilment business must do in Regulation 8.