anyone?

Try pulling up same customer ageing but this time just do an aged receivable rather than an aged 'overdue' - most likely you will see your answer there.
Also check your Data Integrity to make sure it is ok.

it is not a receivable but rather a payable. Data integrity is ok.

I don't do my prepayments that way.. but I have a suggestion... what if you made another prepayment only with the number as -300 instead of 300. In a sense that would make the number the opposite of what is in there. than when you bring up the customer to make the payment you check that 300 off. Perhaps this will balance it . if you are interested in finding out how I do my prepayment send me an email so I can show you a way to do them so they are always available to delete, correct etc. [email protected]

Sorry for not getting back to you sooner. I think what you need to do is to ask the vendor to send you a detailed transaction listing for the past year so that you can cross reference against your detailed ageing. Another thing you could do is to pull up your aged payable for that vendor (not aged overdue) for something like 999 days and using today's date to see all transactions then go thru to see if any of the payments made against invoices matches any of the prepayments showing. Or if the prepayment of 1185.00 was used against a smaller invoice amount a few times thereby resulting in 300.00 left to apply to an invoice. If you have been doing the monthly bank recs then are these payments still showing as outstanding or has the vendor already deposited these chqs into his bank account? If the bank has been reconciled then you can' just write it off without verifying if the payments were for invoices that were never posted into Simply or requesting the vendor to issue a refund chq for the overpayments.

You cannot do a negative prepayment. I've never had an issue with using prepayments before. Obviously something went wacky somewhere. The outstanding invoice and the prepayment are the only 2 items still showing up for this client, but still won't let me clear them.