In your Ledger Report, you'll see that the Transaction Type column notes whether the transaction was either a Payment, Refund, or Adjustment.  An adjustment is the monetary sum listed when a fee has been paid but then the amount due in the payment step is modified, resulting in the need for either an additional payment or partial refund.  For instance, if $800 is rightfully paid on a record but then the fee in the system is changed to be $600, a -($200) adjustment would be listed on your ledger report.  If this happens, make sure to check your payment step to see how much money has been paid as well as any potential refund owed.
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