Definition:
An Individual Taxpayer Identification Number (or ITIN) is nine-digit number issued by the IRS to individuals who must have an identifying number but who are not eligible for a Social Security Number or an Employer ID Number. ITIN's cannot be used for identification purposes. You must get a Social Security number from new employees to be used on Form W-4. An ITIN cannot be used to authorize work in the U.S. or provide eligibility for Social Security or other benefits.
Examples of individuals who might need an ITIN:
- Non-resident alien filing a U.S. tax return and not eligible for a SSN
- U.S. resident alien (based on days present in the United States) filing a U.S. tax return and not eligible for a SSN
- Dependent or spouse of a U.S. citizen/resident alien
- Dependent or spouse of a non-resident alien visa holder.

