A Customer Request can be invoiced to any account on the system which is defined as "Internal" - these are preset within the Sales Ledger.
Change the invoicee to Internal will display the following :-
The internal account can be selected by either entering the account no directly, or by typing in any part of the name of the account and clicking the "Search" button :-
Double click on the account that is required.
Finally, confirm by click "OK".
Unless the labour rate or parts pricing has been specifically overridden as part of the job processing, the Request will be costed at the Internal Account's predefined parts & labour rates or the standard internal rates if the account does not have any specific rates defined.