3 pages

Reversal

Jun 23, 20268 min read

Double Charges: The Hardest Problem in Payments Is Remembering You Already Did

A duplicate charge is rarely a coding bug. It is a distributed system losing certainty about whether an authorization already happened — and then guessing wrong. Why blind retries …

May 25, 20268 min read

Partial approvals: what terminals and hosts must do when the card pays only part

A partial approval is not a decline and not a completed sale. ISO 8583 response codes and amount fields must be read together — and the terminal must not show a green APPROVED …

Apr 20, 202610 min read

Reversals, Refunds, and Chargebacks: Decoding the Payment Lifecycle

Three words every payment professional uses — and confuses. Each lives at a different point in the settlement lifecycle, under a different protocol, with radically different …