Flex Secures $60M to Build AI Finance Tools for Mid-Market Companies
Published: 05 Dec 2025
Flex, a Miami-based AI startup, raised $60 million in a Portage Ventures-led Series B, putting its valuation near $500 million, per sources. The company positions itself as a private bank for high-net-worth business owners and is pushing hard into finance automation for mid-market firms.
Over the past year, Flex says it quadrupled revenue and grew annualized payments volume from $1 billion to $3 billion. That traction comes from focusing on profitable companies with $3 million to $100 million in revenue-an often overlooked segment in financial services.
As the founder put it, "Middle-market business owners employ 40% of Americans, but the financial system has never been designed around their complex needs." Flex's pitch is simple: consolidate cards, payments, working capital, and expense tools into one operating system so teams stop juggling a patchwork of point solutions.
Why finance leaders should care
The headline is the money, but the story is the architecture. Flex plans to ship an AI suite that acts like a back-office team: cash-flow, underwriting, ERP, and expense agents working in concert.
- Cash-flow agent: Forecasts receipts and disbursements, flags shortfalls early, and suggests drawdowns or payment timing adjustments.
- Underwriting agent: Accelerates credit decisions using banking, ledger, and operational data to size and price working capital with tighter risk controls.
- ERP agent: Automates reconciliations, exception handling, and categorization-improving close speed and reducing manual work.
- Expense agent: Enforces policy in real time, captures receipts, and highlights fraud or waste before it hits the books.
What to validate in a pilot
- Integrations: Which ERPs and banks are natively supported? Depth matters (journal entry detail, multi-entity, custom segments), not just "check-the-box" connectors.
- Controls and audit: Role-based access, maker-checker workflows, immutable logs, and evidence export for auditors.
- Security and compliance: SOC 2, PCI for cards, data encryption, and data residency options.
- Working capital terms: True cost (APR + fees), utilization flexibility, covenants, and how rates adjust with risk.
- Forecast accuracy: Baseline your current cash forecasts, then track error reduction, DSO/DPO shifts, and cash conversion cycle improvements.
- Portability: Data ownership, export formats, and the effort required to exit without disruption.
The mid-market thesis
Most fintech products skew to micro-business or enterprise. Flex is concentrating on the firms in the middle-profitable, complex, and leanly staffed. If they deliver, finance teams get fewer systems to reconcile, cleaner data, and more proactive cash management.
Portage's Jake Bodanis summed up the bet: "Flex is building a category-defining financial institution... Middle-market business owners are both massively underserved and extremely valuable to customers when given the right financial infrastructure. Flex's hypergrowth and best-in-class capital efficiency speaks to how powerful this model is."
For context on how significant this segment is, see independent middle market data on employment and revenue contribution.
Bottom line for CFOs and controllers
If you're evaluating Flex, frame it as a consolidation and automation play with cash impact. Start with a scoped pilot (AP/AR + expense) and a clear scorecard: forecast error, days to close, payment fees, working capital utilization, and team hours saved.
Want to map the broader toolset before you commit? Browse a vetted list of AI tools for finance to compare capabilities and build your shortlist.
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