Brex and AI accounting platform Puzzle announced Tuesday a partnership that reduces startup accounting setup from a weeks-long process to a single click, addressing what executives describe as a critical but often overlooked barrier to startup success. The integration, available immediately to Brex’s more than 30,000 customers, allows founders to establish complete accounting systems directly within their existing Brex dashboard without switching platforms or manual data entry. The partnership marks Brex’s evolution from a corporate credit card provider to a comprehensive financial operating system for growing businesses. The partnership addresses a persistent pain point in the startup ecosystem: while founders can quickly establish banking relationships and obtain corporate credit cards, setting up proper accounting systems has remained a complex, expensive process that many defer until it becomes critical for fundraising or compliance. Traditionally, startup accounting setup required founders to interview multiple bookkeepers, navigate sales processes, obtain quotes, and grant access to financial credentials across various platforms — a process that typically took four to six weeks and cost upward of $5,000 monthly just to get started, according to Puzzle CEO Sasha Orloff. The timing problem proves particularly acute because accounting becomes essential precisely when startups need it most urgently — during fundraising rounds, tax season, or acquisition discussions. The technical foundation for the partnership rests on APIs that Brex developed specifically to enable such integrations — infrastructure that previously didn’t exist in traditional banking. When a Brex customer clicks the accounting tab in their dashboard and selects Puzzle, the system automatically creates a Puzzle account, maps expense categories to the appropriate general ledger accounts, and begins syncing transaction data in real-time. The integration includes metadata like receipts, memos, and transaction context that enables AI-powered categorization and compliance checking. Puzzle’s AI system can provide what Orloff calls different “modes” of financial analysis — including “Steve Jobs mode” for direct feedback, “VC mode” for investor presentations, or “friendly mode” for positive reinforcement during challenging periods. Brex generates more revenue as companies grow and spend more, while Puzzle’s automated accounting becomes more valuable as transaction volumes increase. The integration launched to early access users last week, with Mok reporting 21-22 signups within the first 24 hours through organic adoption alone. Unlike traditional accounting software that requires companies to migrate between platforms as they grow — from Excel to QuickBooks to NetSuite — both Brex and Puzzle are designed to scale with companies from incorporation through significant revenue milestones.