NAB glitch duplicates Visa transactions

A "technical error" in National Australia Bank's payment system has caused the bank’s Visa debit customers to be charged twice for transactions made over the weekend.

The bank notified customers this morning that they may notice duplicated credit card transactions appearing on their statement for any Visa debit card purchases made after the close of business trading on Friday. 

“These transactions may be appearing multiple times when viewing your transaction history. We apologise for the inconvenience and are working on a fix as soon as possible,” the bank told customers.

While the affected transactions occured over the weekend, the actual duplication occured this morning.

NAB asked customers not to contact merchants for a refund, and said it was working on resolving the issue as quickly as possible.

The issue is understood to only have affected transactions in which NAB customers selected the "credit" option when making purchases with their NAB Visa debit card.

NAB did not quantify how many users were affected nor how much it would have to repay by the time of writing. 

A temporary fee-free overdraft facility was available to customers in immediate need of cash, a spokesperson said.

Update: The issue was resolved for customers at 11:45am and duplicated transactions have been reversed, a spokesperson told iTnews.

Affected customers will begin to see corrected bank balances from midday today, while transaction histories will be updated overnight. The spokesperson said no overdrawn fees will be charged for those affected.