Architecture implemented in the 1980s is stalling software use with new system design needed to make better use of CRM.

Andrew Purcell, Unisys Global financial services partner said these systems are suffering from "customer interface complexity".

Purcell added Australian banks need to change from an account-centric model to a customer- centric model within the next two years in order to stem the complexity.

"We are not talking about re-engineering everything, just what we need to do which are the customer-facing elements," Purcell said.

"The focus in previous decades was on operational excellence rather than customers; systems that work well don't necessarily service the customers; investments are being wasted."