Zamp, a vertically integrated sales tax compliance platform, has raised $30 million in total funding and announced the global launch of Zamp OS, which it describes as the Operating System of Sales Tax. The latest round was led by Acrew Capital with participation from Thomson Reuters Ventures and several of Zamp’s accounting firm partners.
Zamp OS is designed to address a compounding crisis in the accounting profession: 75% of U.S. accountants are expected to retire in the next 15 years, while compliance workloads continue to grow. The platform enables accounting firms to offer fully managed sales tax compliance to their clients without building a dedicated sales tax practice. More than 120 accounting firms currently use Zamp, including Withum, Anchin, Frank Rimerman, and Larson Gross, with 97.8% client retention in 2025.
What distinguishes Zamp OS from other compliance platforms is its end-to-end ownership of the entire process. The company sources its own tax data across more than 12,000 jurisdictions, owns every workflow from registration to filing to notice management, and pairs AI agents with in-house tax and legal professionals at each step. Because Zamp controls data, agents, human judgment, and execution end to end, the company offers a penalty guarantee: if Zamp gets it wrong, Zamp covers the cost.
Since launch, the platform has remitted more than $300 million in sales tax, completed more than 100,000 on-time filings, handled more than 75,000 notices with 99.97% filing accuracy, and increased output per compliance resource by 12 times. Zamp now provides sales tax coverage in more than 100 countries.
The platform integrates into firm workflows through three access points: embedded directly into a firm’s own product under their brand, through Zamp’s partner dashboard with full client visibility, or via Zamp’s Model Context Protocol, which gives firms access to compliance status inside their existing tools and AI workflows.
KEY QUOTES:
“Three years ago we were only a managed service. Today, we’re an operating system, and the difference is infrastructure. We source our own tax data. We own every workflow. We deploy agents across every step with tax professionals there when it matters. That’s the part people get wrong about AI. It doesn’t replace the team. It gives them leverage. That’s why Acrew Capital and Thomson Reuters Ventures are backing us to scale globally.”
Rohit Bhadange, CEO and Founder, Zamp
“Thomson Reuters Ventures invests in innovative companies that align with our strategic objectives and the markets we serve. In accounting and tax compliance, firms are facing a talent shortage and the work is not slowing down. Zamp has built a vertically integrated platform where AI agents empower tax professionals to work fast and guarantee the outcome together. That’s the infrastructure layer this industry has been missing, and we are thrilled to work with the Zamp team as they lead the way.”
Tamara Steffens, Managing Director, Thomson Reuters Ventures
“When we evaluated the tax compliance landscape, most of the new entrants were building automation on top of third-party data, the same approach the incumbents use, just with a modern UI. Zamp took a fundamentally different path. They built their own tax data layer across 12,000-plus jurisdictions, own every workflow from registration to filing to notice management, and pair AI agents with real tax professionals at every step. That vertical integration is what separates infrastructure from software, this approach provides higher-fidelity outcomes for customers and a durable long-term advantage for Zamp, which is why they can guarantee the accuracy of every filing they touch.”
John Gardner, Partner, Acrew Capital
“As an advisor who works closely with taxpayers navigating the complexities of sales tax, we consistently recommend Zamp. Their deep expertise, responsiveness, and unwavering commitment to supporting Withum’s clients make them an exceptional partner. Zamp’s team goes beyond compliance, they provide the clarity and confidence our clients need in an increasingly complex tax environment.”
Courtney Easterday, MSA, SALT Senior Tax Manager, Indirect Tax, Withum
