Definition of 'Joint Return'
A U.S. income tax return filed on behalf of a married couple, resulting in a combined tax liability. Married taxpayers can choose to file two separate tax returns or a joint tax return. The joint return is often referred to as married filing jointly (MFJ). In order to file a joint return in any given year, the couple must be legally married on or before the last day of the year, and both spouses must agree to file a joint return.
Investopedia explains 'Joint Return'
The Internal Revenue Service (IRS) states, "If you and your spouse decide to file a joint return, your tax may be lower than your combined tax for the other filing statuses. Also, your standard deduction (if you do not itemize deductions) may be higher, and you may qualify for tax benefits that do not apply to other filing statuses." Both spouses report all income, deductions and credits on a joint tax return, and both spouses must sign the tax return. If one spouse dies during the year, the surviving spouse can still file a joint return for that year. During subsequent years, the surviving spouse can file as a surviving spouse, as head of household or as a single taxpayer. If taxpayers divorce at any point during the year, they are considered unmarried for that entire year and cannot elect "married filing jointly" as their filing status.
In general, the joint return provides more favorable tax benefits than filing separately. However, each case is different and taxpayers must determine which method results in the lower combined tax.