How do I allocate a cashbook payment to an invoice?

 In

On the “Cashbook” screen, there is a “Line Details” section at the very bottom which relates to the line (transaction) that you are currently on.  To allocate a payment to an invoice, select the invoice number to which it pertains from the “INV” dropdown box in the “Line Details” section (at the very bottom of the screen).

Watch a video tutorial on the Cashbook and/or Invoice Payments.