Retention Release write off

Hello Friends

I have a retention balance left on a PO and want to write off the retention, is there any way to get rid off retention?

I am thinking of creating a retention release and make dummy payment? -  this iwll have an impact on accounting

What if creating a retentuon releae  and credit memo? - At the time of payment it creates a HMRC invoice, though we cancel this invoice manually it still appears in CIS monthly returns report

INputs are sincerely appreciated

Thanks in advance

Dilip