The hubs, which allow people from different banks to deposit and withdraw money, will open only after suitable premises have been found.
In total, plans for 38 of these shared branches have been outlined, but only four have opened.
Thousands of regular bank branches have closed in recent years, as many customers move online.
A total of 87 branches have been slated for closure by High Street banks so far this year, including announcements by NatWest.
That has raised concerns that many people who struggle with digital services, and small businesses that need to deposit their takings locally, would be severely impacted. Many could struggle with getting access to any cash.