Normalize the denominator
Statements may report gross sales, net sales, settled volume, or funded volume. Record which amount each fee uses. Separate percentage charges, per-item charges, monthly charges, minimums, and one-time adjustments.
Effective rate is total processing cost divided by a clearly defined volume for the same period. It is a diagnostic, not a substitute for line-item review.
- Gross and net volume
- Transaction count
- Pass-through charges
- Processor markup
- Other fees
Investigate changes by driver
A cost change can come from volume mix, card type, channel, ticket size, qualification data, dispute activity, or pricing. Compare like periods and preserve statement versions.
Reconcile fees to deposits and general-ledger entries so an unexplained adjustment cannot hide in a net number.
Recalculate every fee category for one statement and explain the difference between total fees and the bank-deposit reduction.