Numeral sells sales-tax compliance software and services to businesses that need to calculate tax at checkout, register in new jurisdictions, file returns and remit payments. The San Francisco company announced a $100 million Series C led by Insight Partners. It will use the funding to develop the product, hire and expand its offering for software, manufacturing, distribution and wholesale companies.

The workflow begins by connecting a customer’s storefront, billing system or enterprise-resource-planning software. Numeral monitors when business activity creates a filing obligation, calculates the applicable rate during checkout, records cleared transactions and uses those records to prepare returns and remit payments. That puts the steps between a sale and a tax payment into one workflow.

Numeral’s free tier monitors tax exposure. Standard customers pay $150 once to register in each state and $75 for each return filed; enterprise accounts can buy custom plans with an API, international coverage and advanced reporting. The model ties most standard fees to registrations and filings rather than a per-user software seat.

Under the hood, Numeral pairs a deterministic tax engine with AI and human specialists. Its product pages say AI helps classify products and maintain rate tables, while the engine handles calculations and specialists answer more complex questions. The point isn’t to let a chatbot improvise tax treatment; it is to automate high-volume work while keeping a person available when the rules don’t fit the default path.

California shows why that combination matters. A law approved June 29 expands sales-and-use-tax treatment beginning January 1, 2027, to prewritten software transferred electronically or accessed remotely, with statutory exclusions. A software seller’s product classification and customer location are therefore among the inputs that can affect what it must collect—the kinds of details Numeral is trying to keep synchronized.

Numeral says more than 3,500 businesses use the service across over 90 countries. It reported a 327% year-over-year increase in transaction volume and expects its tax engine to process more than 80 million transactions. Founded in 2023, the company has now raised $157 million; its previous $35 million Series B was announced in September 2025.