TfL said the work will make it easier for members to view all the journeys they made in the past year and use multiple account keys.
The three-year-old scheme, sponsored by Barclays and operated by Serco, currently has more than 8,000 bikes available from 14,600 docking points.
As part of the expansion plans, more than 6,000 new docks will be installed. After this upgrade, TfL will start work on allowing “one-swipe” hire with contactless credit or debit cards.
“We are sorry for any inconvenience the upgrade may cause to people wishing to hire [a] bike on 15 September,” said general manager Nick Aldworth.