beta This part of GOV.UK is being rebuilt – find out what beta means

HMRC internal manual

Repayment Claims Manual

Manually issued payable order: What you must do

As the RE in charge of postal arrangements you must check that you

* keep the sealed envelopes under lock and key until they are posted
* put the batches of envelopes into a securely closed mail sack when the outward mail for the day is despatched.