Flex is building a unified financial operating system for the 'missing middle' of American business: companies generating roughly $2 million to $100 million in annual revenue. These firms are consistently underserved, too large for off-the-shelf small-business products yet too small to command the attention of private banking. Flex's answer is a single platform that combines private credit, business banking, treasury functions, payments, and even personal finance management for owners, all enhanced with AI.
By bringing these traditionally fragmented financial functions together, Flex aims to give mid-sized business owners the kind of integrated capital, cash management, and credit access that larger enterprises take for granted. The platform layers AI across these functions to automate financial operations, optimize cash, and provide intelligence that would otherwise require a dedicated finance team or a private banker.
Flex was founded by Zaid Rahman. The company's traction has been rapid: payment volumes reached $3 billion over the trailing year, tripling from the prior 12 months, a sign of strong demand from mid-market businesses for a consolidated financial stack.
In December 2025, Flex raised $60 million in a round led by Portage Ventures, at a valuation of roughly $500 million. The raise brought total equity raised to $105 million. The funding reflects investor enthusiasm for fintechs that pair financial infrastructure with a compelling AI narrative, and for products that target a large, structurally underserved segment of the economy.
Flex's strategy is to become the default financial platform for mid-sized businesses by consolidating credit, banking, treasury, and payments, then using AI to make those functions smarter and more automated. As payment volume scales, the platform gains data and network effects that can deepen its credit and treasury offerings, reinforcing its position with the mid-market companies it serves.