Tax
ITIN
Also known as Individual Taxpayer Identification Number
An ITIN, or Individual Taxpayer Identification Number, is a nine-digit number the IRS issues to individuals who have a US tax filing obligation but are not eligible for a Social Security Number. An ITIN is used for personal tax filings and does not authorise work or confer immigration status.
In plain terms: A personal tax number for people who must file US taxes but cannot get an SSN.
Why it matters
Needed when a filing obligation actually arises — a Form 1040-NR, a personal treaty claim, or withholding on a partnership share. It is not needed to own an LLC, to obtain an EIN, or to open most business bank accounts, and it takes considerably longer to get than an EIN.
Common misunderstanding
Applying for one pre-emptively because a formation service said an EIN requires it. That is the single most costly piece of misinformation in this category.
Read the full guideEIN and ITINRelated terms
Source: IRS — ITIN. This is a definition, not tax or legal advice — verify against the primary source before acting.