Bill payments
All you need to specify is the contact to which the bill payment was made.
DoubleAgent will find the earliest unpaid bill for your contact. If the payment is enough to settle the bill, DoubleAgent will do so.
If there is money left over from the payment, the process starts again: DoubleAgent looks for your contact's earliest unpaid bill and pays it if possible.
We always recommend doing a dry run (by clicking the Dry Run button) to see whether your rule does what you want.