PAYE28030 | Employer records: modified PAYE schemes: payment card reward scheme
From HM Revenue & Customs · PAYE Manual
A payment card reward scheme is
A scheme set up by a payment card company, bank or building society to tax payments of cash made to an employee or third party retailer (who passes it on to their employee) as a reward for the recovery of a lost or stolen payment card or cheque guarantee card
PAYE20065 gives further details.