An ITIN is a tax processing number the IRS issues to individuals who need a US taxpayer identification number but are not eligible for a Social Security Number. It is issued to a person, not a business, and is used for filing obligations and certain treaty claims - it does not confer work authorisation or immigration status.
Why does ITIN matter for founders?
Founders frequently start an ITIN application believing it is required before the company EIN, lose months, then discover the EIN could have been requested immediately. Treat the ITIN as a separate question that arises later, typically for a personal filing or a treaty claim that reduces withholding.
Where can I read more about ITIN?
Note: A plain-English definition for orientation, not legal or tax advice. Rules change - last checked 2026-07-21.