Individual Taxpayer Identification Number (ITIN) Definition
ITIN or Individual Taxpayer Identification Number is a 9-digit number issued by the IRS to make taxpaying simpler for non-resident aliens and individuals without a SSN.
The ITIN is applicable on foreign nationals who are not entitled to a SSN, allowing them to pay taxes legally. All ITINs begin with the digit 9. Individuals who cannot avail a Social Security number are still required to pay taxes and include non-resident aliens, resident aliens, and spouses of U.S. citizens.