Flagstar Bank, N.A. (NYSE: FLG) has selected Finxact, a cloud-native core banking platform owned by Fiserv, Inc. (NASDAQ: FISV), to replace its legacy core banking technology, the companies announced.

Finxact will serve as the transaction processing engine and system of record under Flagstar's broader technology initiative, called the Flagstar S2 Platform. The bank plans to migrate to the new platform in phases.

Flagstar, which reported $87.7 billion in assets as of June 30, 2026, operates approximately 340 locations across nine states. The bank said the move to Finxact is intended to enable real-time transaction processing and eliminate end-of-day batch reconciliation.

Christopher Higgins, Chief Information and Operations Officer at Flagstar Bank, said in a statement that Finxact "will give us the freedom to move faster, grow smarter, and deliver the kind of real-time, seamless experiences that today's customers expect."

Finxact is built on an API-first architecture and is designed to allow financial institutions to add capabilities incrementally. Fiserv acquired Finxact in 2022.

Srini Krish, Co-Head of Financial Solutions at Fiserv, described Flagstar's adoption as "a powerful demonstration of what a next-generation core platform can enable for a large financial institution."

Financial terms of the agreement were not disclosed.