Sphere Raises $21M Series A to Automate Global Tax Compliance
Sphere, the AI-native cross-border tax compliance platform, announced a $21 million Series A led by a16z. Y Combinator also participated in the round.
The company previously raised a $4.3 million seed round led by Felicis, with participation from Pioneer Fund, Y Combinator, and 20VC.
Sphere handles the entire indirect tax lifecycle: registration, calculation, filing, and remittance across over 100 jurisdictions. Companies have to collect tax on customer purchases and remit it to authorities each month or quarter, and Sphere automates this entire process.
Founder Nicholas Rudder built Sphere after experiencing tax pain firsthand at his previous startup, an educational marketplace called ScholarSite. "Marketplaces are liable for tax on their entire GMV not just their take rate, so every new country meant a maze of registrations, filings, deadlines, and risk," he told TechCrunch. "It became a constant distraction."
In 2023, Rudder pivoted to tax compliance software. After two years in stealth, Sphere emerged in late 2024 and has since signed customers including Lovable, Replit, ElevenLabs, Windsurf, and Deel.
At the core of Sphere's platform is TRAM, its Tax Review and Assessment Model. "TRAM ingests and codifies the rules in every jurisdiction and creates a set of tax determinations along with reasoning and backing citations for that determination," Rudder explained. Sphere's team reviews TRAM's outputs before they're pushed into a tax engine that applies tax to transactions in real time.
Since launching, Sphere has been growing revenue by more than 30 percent each month. The company is one of only three tax vendors globally with a native integration to Stripe's Billing and Checkout products.
Marc Andrusko, the a16z partner who led the deal, said the firm first met Rudder when he was working on ScholarSite. "While we didn't get all the way to a term sheet for that business, it was clear Nick had the horsepower, grit, and drive needed to be an exceptional founder," Andrusko told TechCrunch.
"Sphere isn't just another vendor. It's a scalable platform built for the next era of compliance. Just as Deel redefined global payroll, Sphere is transforming revenue-based compliance."
— Marc Andrusko, Partner at a16zThe Series A will fund expansion into more jurisdictions, AI and engineering hires, and international sales operations. Rudder envisions Sphere expanding beyond indirect tax into areas such as input tax, withholding tax, e-invoicing, and tariffs.