For its online banking application the group chose a "packaged approach" with Fiserv from Corrillian, which Girn says is renowned for innovation with Web 2.0 technologies and allows "more customer choice".

Following integration of the "bare essentials" like connecting the ATM networks, the intranet sites and e-mail systems, some "heavy lifting" was done integrating the general ledger and HR systems.

"Using the old traditional approach of the bigger business clobbering the smaller business was not our strategy," Girn said. "We picked the best [and] the treasury part of the business will be migrating off St. George to Westpac which his more robust."

The phase Westpac is at now is investing in strategic direction to simplify what it uses. The group recently converged onto one credit card system and as a result St. George customers will start receiving a higher level of security with chips on cards from early next year.

Girn said customers are also increasingly using Web 2.0 channels for exchanging information the group has a team of people responding to people via Twitter and Facebook.