The newly merged Co-operative Financial Services (CFS) and Britannia Building Society have a long IT journey ahead of them if they are to see the true benefits of their merger.
The first step for companies, which formalised their merger this week, is to decide which IT platform to use.
A bank spokesman said nothing has been decided yet. "Clearly there is a huge piece of work to do to decide what systems to use going forward," he added. "But as the companies come together it will become clearer."
The companies began talks to merge in October but Britannia said unlike other mergers in the financial services sector the talks were not the result of the credit crunch.