The contract item for which retainage is being billed has a negative retainage balance consisting of multiple negative invoices. When retainage is billed in Billing, the retainage billed is proportionately distributed to the invoices it was held on. When these are negative invoices, the software is unable to round the amounts correctly resulting in an overbilled retainage for the contract item.

There is not a way to partially bill the negative retainage though Billing due to the rounding issue and Accounts Receivable does not allow billing of negative retainage held.

You must through Billing bill 100% of the negative retainage held and offset this by billing a larger amount of retainage on a positive item to obtain the same net amount of retainage billed.