Flex raises $60m Series B to scale AI private bank

December 4, 2025

Flex, the AI-native private banking platform for high net worth middle-market business owners, has secured $60m in a Series B equity round led by Portage, bringing its total equity raised to $105m.

The round also had participation from CrossLink Capital, Spice Expedition, Titanium Ventures, Wellington, Companyon Ventures, Florida Funders, FirstLook Partners, Tusk Venture Partners and others.

The fundraise comes as the company responds to accelerating demand from business owners who struggle with fragmented financial workflows. Running a profitable middle-market company requires navigating numerous disconnected systems, and Flex aims to replace this complexity with a unified finance platform.

Founded in 2023, Flex builds financial infrastructure for high net worth business owners who generate between $3m and $100m in revenue. The platform combines private credit, business and personal finance tools, payments capabilities and ERP functions into a single ecosystem.

Flex’s new capital will support the launch and scaling of Flex Elite, its invite-only consumer card and membership programme. The product is positioned as a direct competitor to the Amex Centurion card and extends Flex’s vision to act as the private bank for ambitious business owners, unifying every aspect of their personal and business financial lives.

The company has experienced a period of rapid expansion, with revenue quadrupling and annualised payments volume tripling to $3bn in the past year. Customers now use an average of four or more Flex products.

Flex is also building AI agents across each product line, supporting functions such as credit underwriting, payments, cash management and ERP operations. These agents feed into a unified “motherboard” designed to operate as an AI CFO for business owners. By streamlining internal workflows, Flex maintains a lean cost base while elevating customer experience through its AI-powered Owner Insights.

The business credit card, offering 60-day float on transactions, has been a major gateway product. Adoption of the card has paved the way for customers to use additional services such as banking, payments, expense management and working capital tools.

Zaid Rahman, founder and CEO of Flex, said, “Our mission is to build the private bank ambitious business owners have always deserved. Middle-market business owners employ 40% of Americans, but the financial system has never been designed around their complex needs. Flex is the first platform that supports every step of their financial lives, from the moment they earn revenue to the moment they spend it personally. Unlike many of our FinTech peers who focus on saving large enterprises money, we focus on helping ambitious owners make more money.”

Jake Bodanis, partner at Portage, said, “Flex is building a category-defining financial institution. The company has proven that middle-market business owners are both massively underserved and extremely valuable customers when given the right financial infrastructure. Flex’s hypergrowth and best in class capital efficiency speaks to how powerful this model is.”