A joint return is a tax return filed with the Internal Revenue Service (IRS) on the new, simplified Form 1040 (as of 2018) by two married taxpayers whose filing status is married filing jointly (MFJ) or by a widowed taxpayer whose filing status is Qualifying Widow or Widower (QW). A joint return allows these taxpayers to combine their tax liability and report their income, deductions, and credits on the same joint return.