A Form 1040-C is not a final return. You must file a final income tax return after your tax year ends.
If you are a U.S. citizen or resident alien on the last day of the year, you should file Form 1040 reporting your worldwide income. If you are not a U.S. citizen or resident alien on the last day of the year, you should generally file Form 1040NR or, if eligible, Form 1040NR-EZ, U.S. Income Tax Return for Certain Nonresident Aliens With No Dependents. However, certain individuals who were resident aliens at the beginning of the tax year but nonresident aliens at the end of the tax year must file a
dual-status return. See Dual-status tax year on page 4.
Any tax you pay with Form 1040-C counts as a credit against tax on your final return. Any overpayment shown on Form 1040-C will be refunded only if and to the extent your final return for the tax year shows an overpayment.