Benefits

In general, filing a joint tax return in the United States gives a couple a lower tax obligation than if the individuals filed separately, according to the Internal Revenue Service. In addition, it takes less time to file the joint return instead of two single returns.

Function

The standard deduction for a married couple is much higher than the single filing deduction. In addition, there are certain tax write-offs available only to those who file a joint return.

Considerations

The benefits of a joint return increase as the disparity between each spouse's income grows, according to ECNext.com.

Warning

The IRS only allows a couple to file a joint return if they are married on the last day of the tax year. In cases where filing as married incurs a greater tax cost than if the couple filed separately, the spouses may not intentionally divorce to lower their tax obligation, known as a "sham divorce."

Disadvantages

Both persons on a joint return are liable for the total tax obligation, even if the couple divorces shortly after filing or one spouse makes significantly more money. Also, married couples have a hard time deducting medical expenses and other miscellaneous itemized deductions.

Source:

Internal Revenue Service; Publication 501

ECNext.com; Tax filing status: are joint tax returns always best?

Lawyers.com; Marriage and Filing Your Federal Tax Return