The contract is believed to be worth almost AU$600,000 in its first year and around AU$120,000 for each year thereafter.
"The contract is for the installation, maintenance and support of Phoneware VXT and ACU [Advanced Charging Utility ACU billing system] software accompanied by a facilities management agreement for up to three years," Phoneware, a Sirius Telecommunications subsidiary, said in a statement to the Australian Stock Exchange.
VXT is a management platform with call accounting functionality for Voice over IP networks. The ANZ Bank has a VoIP implementation supplied by Nortel Networks.
The news comes as Westpac recently announced it had contracted Telstra to provide AU$400 million in telecommunications services over the next five years.