Sphere, born from a founder’s frustrations with cross-border tax chaos, is building an AI-native compliance platform to automate the entire tax lifecycle for globally scaling companies.
From Edtech Pivot to AI Tax Engine
Nicholas Rudder, once co-founder of edtech startup ScholarSite, faced a frustrating truth: global expansion brought with it a tangle of international tax compliance obligations. Rather than become an accidental tax expert, he pivoted—and Sphere was born.
- Initially an educational marketplace, Sphere reemerged in 2023 as a full-fledged AI-native tax compliance platform.
- On Tuesday, the company announced a $21 million Series A led by Andreessen Horowitz (a16z), with participation from Y Combinator and Felicis Ventures.
- The new funding brings Sphere’s total capital raised to over $25 million.
Built for Global-First Companies
Sphere is designed for Series B to pre-IPO companies expanding globally—those that must manage tax collection and remittance across dozens of jurisdictions.
- It handles the entire indirect tax lifecycle, including:
- Registration with over 100 global tax authorities
- Real-time tax calculation
- Filing and remittance to governments
- Clients include fast-scaling platforms like Replit, Lovable, and ElevenLabs.
“It’s the product I wish I had when building my first company,” said Rudder, now CEO.
AI at the Core, But Not Where It Can Fail
At the heart of Sphere’s platform is TRAM — the Tax Review and Assessment Model, which codifies jurisdiction-specific rules to determine:
- Whether a transaction is taxable
- Why it’s taxable (or not), with full citations and reasoning
TRAM’s outputs are then human-reviewed before they’re deployed. This AI component sits upstream, ensuring accuracy while avoiding hallucinations in live transaction processing.
“The part that applies tax in real time has no AI, so there’s zero chance of hallucinations,” Rudder emphasized.
Deep Integrations Drive End-to-End Automation
Sphere stands apart through deep integrations with platforms and tax authorities alike:
- Native connections with Stripe Billing and Checkout—one of only three tax vendors globally with this capability
- Plug-and-play integrations with billing tools like Campfire
- API-based access to 100+ tax jurisdictions, eliminating reliance on third-party consultants
Once registration is submitted, Sphere automatically tracks, files, and remits taxes, even debiting returns from company bank accounts for seamless compliance.
Backed by a16z’s Fintech and Compliance Bet
Sphere’s backers see it as a long-overdue upgrade to outdated compliance infrastructure.
“Legacy players often hand clients off to third-party firms,” said Marc Andrusko of a16z. “Sphere built local integrations and AI automations that manage the entire process end-to-end.”
Andrusko said a16z had tracked Rudder since his ScholarSite days, and quickly moved once it was clear Sphere was his next venture.
- Sphere spent two years in stealth, quietly building its product and team.
- The Series A will fund expansion into more jurisdictions, AI and engineering hires, and international sales operations.
A Tool Built for Finance Teams — Not Tax Experts
Rudder envisions Sphere as more than just a tax compliance tool.
“I want it to be the go-to system for any transactional compliance exposure, not just indirect tax,” he said.
In a world where marketplaces, SaaS platforms, and digital-first companies increasingly operate across borders, Sphere wants to automate the red tape so companies can scale with confidence.
