Use
You can use transaction FLB1 to select checks by lockbox number, status, and/or batch number, and then postprocess them.
As part of postprocessing, you branch to payment advice maintenance, where you can add, change, or delete clearing information. You can use "Reason codes" to classify deductions; you can then post a deduction to the G/L account or as a remaining item in the customer account.
Once you have changed the payment advice, you can try to post it again. To this end, you can choose from the following modes:
Procedure
To postprocess lockbox data, proceed as follows:
You reach the initial screen.