They are:
Stay in Compliance with Tax Laws. An ITIN number allows you to comply with U.S. tax laws if you are earning income, transacting business in the United States, or if you have a tax filing requirement, and do not have a social security number.
Filing Taxes: You can use your ITIN to file federal income tax returns, claim tax refunds, and fulfill your tax obligations.
You may also claim certain tax credits if you qualify.