Tax
SSN
Also known as Social Security Number
An SSN, or Social Security Number, is a nine-digit number issued by the US Social Security Administration to citizens, permanent residents and certain visa holders. It identifies an individual for tax, employment and benefits purposes. Owning a US company does not require an SSN.
In plain terms: A US personal ID number. You do not need one to own a US company.
Why it matters
Its practical relevance to founders is what it unlocks in speed: with an SSN the IRS issues an EIN online in minutes, and US personal credit history exists to underwrite business borrowing. Without one, both are slower rather than impossible.
Read the full guideEIN and ITIN