Flex Raises $60 Million Series B, Reaches $500M Valuation as It Builds an AI-Native Financial Platform for Mid-Market Business Owners
San Francisco, December 2025:
U.S.-based fintech startup Flex has raised $60 million in a Series B funding round, bringing its total equity funding to $105 million and valuing the company at approximately $500 million. The round was led by Portage Ventures with participation from Wellington Management, Titanium Ventures, CrossLink Capital, Companyon Ventures, Florida Funders, and others.
The fresh capital will accelerate Flex’s mission to build a complete, AI-first financial operating system for mid-sized businesses earning between $2 million and $100 million annually — a segment the company refers to as America’s “overlooked wealth creators.”
Flex’s Target Market: The Underserved Mid-Market Business Segment
Flex focuses on a high-value but traditionally underserved segment of the U.S. economy:
- Businesses generating $2M–$100M in annual revenue
- Companies “too big” for small-business fintech tools but “too small” for private banking
- Owners who often manage multiple entities, complex cash flow, and significant personal wealth
- A segment that collectively accounts for nearly 40% of U.S. payroll
This market represents hundreds of thousands of businesses that lack integrated finance, credit, payments, and wealth tools under one platform.
Company Profile: What Flex Does
Founded in 2022, Flex is building an integrated financial infrastructure designed specifically for owners of mid-market businesses. The platform combines:
✔ Business Banking & Cash Management
- Operating accounts
- Cash optimization tools
- Treasury insights
- Entity-level money movement
✔ Payments, Billing & Expense Automation
- Vendor payments
- Automated bill pay
- Expense classification
- Multi-entity bookkeeping
- ERP-style workflows
✔ Business Credit & Working Capital
- Up to 60-day float on Flex business card
- Revenue-based underwriting
- AI-powered credit engine using multi-entity data
- $200M+ in available credit facilities (from earlier funding)
✔ Personal Finance & Wealth Tools
- Unified personal + business dashboard
- Premium rewards & lifestyle benefits
- AI wealth insights
✔ AI-Native Core Technology
Flex’s proprietary AI agent framework automates:
- Underwriting
- Back-office workflows
- Expense management
- Forecasting
- Multi-entity accounting
- Fraud detection
- Cash flow management
This allows Flex to offer enterprise-level infrastructure at a lower cost base compared to legacy banks and traditional fintech stacks.
Leadership
Zaid Rahman — Founder & CEO
An experienced entrepreneur and technologist, Rahman leads Flex’s vision to create a complete “financial home” for America’s mid-sized business owners.
Leadership Focus Areas:
- AI-native financial automation
- Multi-entity financial management
- Credit underwriting innovation
- Integrated business + personal finance
Funding Timeline & Key Milestones
Series B — December 2025
- Amount: $60M equity
- Led by: Portage Ventures
- Valuation: ~$500M
- Goal: Scale AI systems, expand enterprise-grade financial tools, launch consumer/lifestyle offerings
Series A — Early 2025
- Amount: $25M equity
- Credit Facility: $200M for financing products
- Valuation: ~$250M
Acquisition of Maza — April 2025
Flex acquired Maza, a fintech app focused on consumers and solopreneurs, expanding its reach and enabling cross-segment services.
Traction (Past 12 Months)
- 4× revenue growth
- Payments volume grew from $1B to $3B
- Team: 80+ employees and growing
Why Flex Is Unique in the Fintech Market
1. A Unified Platform for Business & Personal Finance
Most fintech tools focus on either business or consumers — Flex combines both.
2. AI-Powered Vertical Integration
From underwriting to accounting, AI agents automate complex, multi-entity workflows.
3. Deep Focus on Mid-Market Companies
This segment is underserved by banks yet has the financial complexity of large enterprises.
4. Credit + ERP + Banking in One System
Flex combines:
- Credit
- Payments
- Back-office automation
- Treasury
- Wealth management
Few fintechs offer this breadth in one product.
Deals & Strategic Partnerships
- $200M credit facility secured earlier in 2025 to support lending products
- Partnerships with banking institutions for cash management
- Acquisition of Maza to expand consumer-finance capabilities
These moves position Flex for further vertical integration and multi-segment financial coverage.
Future Plans: What’s Next for Flex
✔ Launch of “Flex Elite” (Invite-Only Card & Membership)
A luxury consumer card for high-net-worth business owners, offering:
- Premium rewards
- Lifestyle benefits
- Concierge services
- Personal finance automation
✔ Deeper AI Integration Across All Financial Workflows
More AI agents across:
- AP/AR
- Payroll insights
- Entity-level accounting
- Tax preparation
- Treasury management
✔ Expansion of Credit Products
- Larger credit lines
- Enhanced underwriting models
- Real-time financing for growing firms
✔ Team Growth & Product Scaling
Hiring across engineering, product, AI, and finance to support rapid expansion.
✔ Positioning as a ‘Private Bank for Business Owners’
Long-term vision: become the default financial home for every mid-sized business owner in the U.S.
Conclusion
Flex’s $60 million Series B marks a major milestone in its ambition to redefine how mid-market business owners manage money. With strong investor backing, rapid revenue growth, and an AI-native approach to financial infrastructure, Flex is poised to become one of the most influential players in the future of business finance.
