When someone says they need to file their taxes, they're talking about filling out a __________________.

When someone mentions the need to file their taxes, they are specifically referring to completing a federal tax return. This document is essential as it provides the government with information about an individual's income, deductions, and credits for the tax year, allowing the Internal Revenue Service (IRS) to determine whether the person owes more taxes or is entitled to a refund.

Filing a federal tax return is a requirement for most Americans, as it summarizes their financial activities for the year and calculates their overall tax liability. This process is critical in ensuring compliance with tax laws and helps individuals report their income accurately.

Other options like tax liability, form W-4, and tax bracket represent different aspects of income taxation. Tax liability refers to the total amount of tax owed, the form W-4 is used by employees to indicate their tax withholding preferences, and tax brackets denote the tax rates that apply to different levels of income. However, none of these terms directly relates to the act of filing taxes in the way that a federal tax return does.