F
Flex
49
Stack Score
Editorial pick✓ Verified working
Flex
AI banking + finance OS for startups.
Try Flex✓ Free trial available
Best for
Best for early-stage US startups wanting one finance OS instead of 4 vendors.
At a glance
- Pricing
- freemium
- Setup time
- 1 day
- Learning curve
- easy
- Last verified
- 5/25/2026
What we love
- ✓Modern all-in-one stack
- ✓AI does the boring bookkeeping
- ✓Free entry tier
Where it falls short
- −Founded for startups — less SMB-fit
- −US-only banking
- −Newer brand vs Brex/Ramp
Pricing
✓ Pricing verified Jun 21, 20262 tiers
Free
$0
per month
- ✓Banking
- ✓Card
- ✓AP
Plus
Custom
per month
- ✓Advanced + integrations
Overview
Flex (formerly Flexbase) is a fintech operating system for early-stage startups — corporate card, banking, bill pay, expense management, and an AI agent that auto-categorizes and reconciles transactions.
Key features
- ●Corporate card + banking
- ●AI auto-categorization
- ●Bill pay
- ●Expense management
- ●Custom approval rules
Best use cases
Startup finance OS
Run banking, cards, bill pay, and bookkeeping from one app pre-Series A.
AI bookkeeping
Let the agent code transactions to GL accounts so the founder doesn't.
Integrations
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