How To Add Ad Hoc Messages To A Bill

If you want to add a message to a completed bill:

Navigate to the Bill - Main page.
Transfer to the Bill - Bill Messages tab.
Insert a new row (click the + button). Note, you can only insert a message on the most recent bill that is Complete.
Specify the desired message code.
Save the bill.
Reprint the bill as per How To Reprint A Bill (For The Original Recipients or For Someone New).

Fastpath:

Refer to The Source Of Bill Messages for more information about the messages the system automatically links to a bill when the bill is completed.