IRS Tax Form 1040NR is the Federal individual income tax return for non-resident aliens. This tax form is similar to the regular 1040 form used by U.S. citizens. Form 1040NR must be filed if you were a nonresident alien during the past tax year who engaged in business in the U.S.. You are required to file even if you have no income from the business, or your income is exempt from #tax under a treaty with your country.