A credit ledger Finance could trust

About 11% of shipments came back: roughly 400 returns a month against 3,600 deliveries. When a supplier had already been paid, Bizongo had to recover the excess from future payables.

In one quarter, 250 such credit notes were worth about ₹16 Cr. Recovering them meant a BI request, a Tally dump, manual matching and a hand-calculated offset.

The existing auto-adjustment used first-in-first-out. It could consume the wrong note, split a large note across many invoices, adjust a note Finance had not approved, or count a duplicate twice.

Before any new code, I insisted on a ground-zero clean-up: mark notes already used as settled, cancel invalid ones, then recalculate balances. New code on corrupted state formalises old errors.

Then a seller-level credit ledger replaced FIFO: approve or cancel each note, pick which notes to apply at payment, prefer the note tied to that invoice, block invalid combinations, and keep an audit trail and reversals.

₹14 Cr of payables cut in a quarter and ₹80 Cr of credit notes processed in a year, with monthly reconciliation effort down 70%.

Utilisation doubled from 28% to 57%, and settlement time fell from eight days to six.

Finance kept the choice; the system kept the rules. Control and usability were the same design problem.