What evidence does a restaurant need before claiming a marketplace commission or fee is wrong?

Keep the signed agreement or current rate card, the full financial statement, the eligible-sales definition, store and period identifiers, the platform’s calculation, and your independent recalculation. Preserve original files and show the formula. A statement-only audit can identify an unusual or unexplained charge, but it cannot prove a contract violation when the governing rate is missing.

Present the issue as a reconciliation packet: expected rate or rule, observed amount, calculated expected amount, difference, affected period, and the exact source rows. Avoid accusatory language until the evidence is complete. The goal is a correction the restaurant can defend, not a dramatic number.