Synonyms for the term "federal tax return" include income tax return, IRS tax return, federal income tax form, income tax declaration, and personal tax return. All of these terms refer to the document submitted to the Internal Revenue Service (IRS) by taxpayers in the United States each year to report their income, deductions, and credits for the purpose of calculating their federal income tax liability. While these terms have slightly different connotations, they are all used interchangeably to describe the same process of filing taxes with the federal government. It is important to note that state tax returns may also need to be filed separately.