State entity numbers, EINs and other business IDs

Updated October 30, 2026. General information, not legal or tax advice.

Every state registry gives each business record a permanent number. States call it different things: Florida’s document number, New York’s DOS ID, Colorado’s ID number, North Dakota’s SOS control ID. The number stays with the record when the business changes its name, so it’s the most reliable way to find one specific company.

Where to find it

• On the business’s formation documents, annual reports and state certificates.
• On the state registry record itself. Search by name, then open the record.
• On some invoices and contracts, especially for regulated businesses.

EINs aren’t public

An Employer Identification Number (EIN) is a federal tax ID issued by the IRS. There is no public EIN lookup. Exceptions: tax-exempt organizations appear in the IRS Tax Exempt Organization Search, and public companies list theirs in SEC filings. If you need a vendor’s EIN, ask them for a Form W-9.

What each state calls its number