Westpac, which provides transaction clearing services for the IPB and other NSW government departments, has identified a slow electronic payment gateway linking its systems to the online fine payment service as potentially causing some individuals to over-pay fines.
It appears that the malfunctioning gateway is delaying the IPB's credit-card payment confirmation process, causing some consumers to have their accounts debited repeatedly.
It's not the first time that that the IPB's online payment system has been under scrutiny over incorrect bank account debits. Many consumers were refunded for multiple fine payments late in April when a bungled system upgrade left the IPBs online credit-card payment system floundering over the ANZAC Day long weekend.
Westpac has defended its e-payment service, claiming that transactions were promptly reversed in the "rare instances" that overpayments occurred.
However, it's difficult to gain an accurate picture of how many consumers have been impacted by the latest problem, with those near the system giving accounts that are confusing at best.
Westpac, the NSW Treasury and the IPB's own customer service staff last week offered conflicting accounts of how frequently consumers had been tripped up by the glitch.
NSW Treasury said last Thursday that measures built into the system to prevent multiple fine payments meant it had not recorded any further instances of multiple debiting since the April long weekend.
"With the IPB system a person can't pay twice basically," said a spokesperson for NSW Treasury.
Westpac, on the other hand told ZDNet Australia  that IPB staff informed the bank that it was handling "some enquiries" from consumers about the problem but that they were "infrequent".
When ZDNet  recontacted the IPB Friday they reinvestigated the matter and conceded that they had discovered one instance of multiple debiting in recent weeks.
An IPB customer call centre operative gave a different account of the situation to both Westpac and the NSW Treasury. She said that the problems with the gateway were known to the IPB and that in some cases thousands of dollars worth of incorrectly debited funds had to be refunded in cases where individuals were paying large fines.
Westpac defended its record as an e-payment service provider. It gave assurances that the IPB had no recorded any instances of customers being re-credited more than 24 hours after an incident of incorrect debiting since it took over the system in March. The bank added that, on average 80 percent of the 3,000 transaction handled by the IPB's online payment system each day were carried out in under two seconds.
"The Internet, as you know is an evolving tool, and we're moving as fast we can with the technology. And, yes, it's not always going to be perfect in every instance but you can see we're making every effort to make it as good as possible".
A spokesperson for Westpac said the bank planned to remove all third-party interfaces from its payment gateway by September to improve the service.
Privately some sources in the commercial finance sector were prepared to admit that the quality of online services was not consistently high across government offerings.
According to the source, it was fairly unusual for an online payment system not to contain some sort of payment verification mechanism to prevent erroneous multiple payments.