You can write to HMRC Payments to ask them to:
send a replacement cheque if yours is lost or out of date
send the repayment to the bank account stored on your business tax account
send the repayment somewhere else because you are no longer VAT registered
use the repayment to pay another tax
You must return cheques that are out of date or you’re not going to use.
HMRC Payments
HM Revenue and Customs
BX9 1XD