BSP's Easter core-banking cutover showed wrong balances and let PNG customers overdraw

Bank South Pacific, Papua New Guinea's largest bank with about 2.5 million retail customers, was implementing a new banking system over the Easter 2023 weekend when a technical error made some customers' balances display incorrectly. Some customers saw money they did not actually have and overdrawn their accounts; others watched their displayed balances drop. One customer, Rosemary, made a 600-kina (about $257) online purchase on the Friday against funds that had been incorrectly allocated to her account, and could not get a refund on the items.

BSP said it 'did not deduct or deposit any funds to any accounts' and told customers who had overdrawn that they would have to repay the bank. It declined to say how much money had been overdrawn. Over the same long weekend, internet and mobile banking were inaccessible; ATMs still worked but with hours-long lines, and a Port Moresby customer said she could not buy breakfast for her children because the system was still upgrading.

Customers reported confusing swings: a Wewak resident saw 107 kina vanish from his displayed balance and waited for the bank's promise to restore it. Some customers threatened to switch banks, complaining about high fees on top of the outage, and the customer who overdrawn said BSP should have tested the upgraded system before applying it to everyone and should have suspended services once it knew of the problem.

Overdrafts left unquantified; internet and mobile banking down over the long weekend for a 2.5-million-customer bank, customers threatening to switch

BSP ran a live cutover of core banking over a holiday weekend, when support was thinnest and customers most needed to pay for daily essentials.

Wrong balances were displayed while services stayed on, so customers could spend money the bank later demanded back.

The bank did not suspend banking services once the error was known, the response an affected customer said should have happened.

BSP declined to disclose how much money customers had overdrawn, leaving the glitch's scale unknown to the public.

Holiday cutovers need a kill switch: once balances display wrong, suspending services beats letting customers spend money they will be told to repay.

BSP posted statements on Facebook and to the ABC saying it was addressing the technical issue, and customers who had overdrawn were told to repay. Some customers said they were considering switching banks, citing the outage and fees. The bank never publicly quantified how much had been overdrawn.