Ledger
The ledger is the append-only record of every financial transaction that has ever happened in a syndicate: usage charges, event fees, shortfalls, periodic dues, expense credits, payments, reversals, manual adjustments. Every member has their own slice of the ledger; admins see all of it.
“Append-only” means transactions are never edited or deleted in place. When a charge is wrong, the admin records a reversal against the payment that settled it and, if needed, a new transaction in the right shape. Both the original and the reversal remain visible forever.
A correction always adds a line to the ledger: a credit for the difference between what the member was charged and what they should have been. What differs is what pays that credit off. When the money goes back to their bank through the payment provider, the credit is discharged in the same moment by the money leaving, so nothing further is owed and the balance does not move. When it does not, the credit stands on the member’s account and is worked off against their next charges. See Reversals.
A member’s balance is computed from the ledger on read. It is not a separately stored number, which is why a reversal is visible the moment it is posted.