What is an EIN?
An Employer Identification Number (EIN) is a unique 9-digit number assigned by the Internal Revenue Service (IRS) to identify a business entity for federal tax purposes. The format is XX-XXXXXXX. Every US business with employees, and most businesses that file federal tax returns, has an EIN. Sole proprietors without employees may use their Social Security Number instead, but obtaining an EIN is recommended for business identity purposes.
The EIN as an AI Identity Signal
The EIN is the most powerful federal identity signal for US businesses in the AI context. Unlike state registration numbers, which vary by state and are not universally accessible, the EIN is a federal identifier that AI systems can use to anchor a business's identity. Including your EIN in your website's Schema.org markup and in your AI Verified passport creates a strong, machine-readable identity signal.
How to Include Your EIN in Schema.org Markup
To include your EIN in your Schema.org markup, add it to the identifier array in your Organization or LocalBusiness schema. The identifier should use the propertyID "taxID" and the value should be your EIN in XX-XXXXXXX format. AI Verified's Schema.org generator automatically includes your EIN in the correct format.
EIN and AI Verified
When a US business claims an AI Verified passport, the EIN is used as the primary federal anchor. The passport includes a cryptographic hash of the EIN, creating a tamper-evident record that AI systems can use to verify the business's identity. Silver tier ($19/month) provides EIN-anchored verification.