IHTM31661 | Assessing: repayments: informing the taxpayer
From HM Revenue & Customs · Inheritance Tax Manual
To inform the taxpayer or agent how much you intend to repay and how long it will take, you should prepare a standard letter SL20 at the same time you prepare the Sect 6 (IHTM31641).
Do not send the letter to the taxpayer or agent:
Prepare the letter, but leave it undated.
File one copy and place the outgoing copy on the front of the file, signed, but without a hole punch.
The Repayment Security Officer will date the letter and send it out when they authorise the repayment.