An ITIN is only available to resident and non-resident aliens who aren't eligible for U.S. employment and need identification for other tax purposes. You can identify an ITIN because it is a nine-digit number, formatted like an SSN, that starts with the number "9" and has a range of numbers from “50– 65,” “70–88,” “90–92,” and “94–99” for the fourth and fifth digits (for example, 9NN-7N-NNNN). An individual with an ITIN who later becomes eligible to work in the United States must obtain an SSN.