RM4104 | RO instructions: Voucher already cancelled
From HM Revenue & Customs · Repayment Claims Manual
If an RA has noted the claim to show that vouchers were cancelled before receipt in your District see below.
If you receive a cancelled voucher from a claimant see below.
If the voucher shows any sign which suggests that it was cancelled before you received it (RM4088 - RM4100) assume that it had been submitted in connection with an earlier repayment claim unless the file shows that the voucher was returned to the claimant or agent before repayment (RM4220)
ask the claimant to explain why the voucher had been cancelled before you received it
if you receive a reply see RM4108.