Tesco Bank has gone live with a new Fiserv platform that is underpinning its fixed-rate savings account.
The bank signed the contract in 2009 and went live in October this year.
Fiserv is also providing technology for financial crime prevention, reconciliation management and electronic document management products.
The bank went live with the implementation on the savings account - its first product to use the Fiserv Signature bank platform - on 6 October. It provides processing and servicing to the fixed-rate saver account.
Tesco Bank is the UK's largest supermarket bank with 6.5 million customer accounts.
Tony Catalfano, division president of bank solutions at Fiserv, said, "Tesco Bank is visionary in its plans to align business processes, IT, data and analytics and service delivery."