One of the most significant factors in determining how much federal income tax you will pay on your earnings for the year is your filing status. Using the correct filing status on your federal tax return is essential for determining your income tax rate and the size of the standard deduction you are eligible to claim, two things that can have a dramatic impact on your tax bill. 

While determining filing status is straightforward for most Americans, it can get difficult for those with complicated family or financial situations.

Generally, married couples filing jointly enjoy tax brackets drawn up to give them the most beneficial tax rates. However, there are situations where widows or widowers can take advantage of the tax rate for married filers for up to two years after their spouse dies. Likewise, some single individuals will qualify for the lower tax rates for heads of households.

Determining Your Filing Status

In general, for individual income tax purposes your marital status on the last day of the year determines your tax filing status for the entire year. If you're unmarried or legally separated from your spouse under a divorce or separate maintenance decree and don't qualify for another status, your filing status is single.

However, your status isn't just limited to whether you're married. The IRS allows the following five statuses:

• Single
• Married filing jointly
• Married filing separately
• Qualifying widow(er) with dependent child
• Head of household

Each of these filing statuses is examined in more detail in the following sections. More detailed information on each filing status can be found in IRS Publication 501, "Exemptions, Standard Deduction, and Filing Information."

Single Filers

The single filing status generally applies to individuals who are unmarried on the last day of the tax year. This includes someone who divorces or separates from their spouse during the year. Some single individuals will also be eligible to file as a widow, widower, or head of household, depending on their situation.

Married Filing Jointly

If you're married at the end of the year, you and your spouse may file a joint return. While you also have the option of filing separately, most married taxpayers will find filing jointly benefits them more financially. Since your marital status is determined on the last day of a tax year, you can file jointly if you get married during the year.

One notable exception to the rule of your marital status at the end of the tax year applying for the entire year is when one spouse dies during the year. In that situation, you can still file as married filing jointly for the year they died. If a taxpayer remarries the same year their spouse dies, they can no longer file a joint return with their deceased spouse but could file a joint return with their new spouse.

When it comes to determining your marriage status, the IRS relies on the laws of your state governing marriage, separation, and divorce.

Married Filing Separately

Sometimes married spouses may benefit financially from filing separate returns with the IRS. Situations where it is sometimes better to file separately include when both spouses have roughly the same income, one spouse has significant medical expenses, or one spouse has significant itemized deductions.

Another situation where a married couple would want to file separately is when one spouse does not want to be liable for the other's tax liability. When married taxpayers file jointly, they are both responsible for each other's unpaid taxes. By filing a separate return, a spouse will only be responsible for the information reported on their return and will not be held liable for their spouse's unpaid taxes and penalties.

Qualifying Widow(er) With Dependent Child

If your spouse died during the previous two years and you have at least one dependent child, you may be able to file as a qualifying widow or widower with a dependent child. This generally allows you to continue to claim the benefits of married filing jointly for up to two years after your spouse dies.

To file as a qualifying widow or widower with a dependent child, you must meet all five of the following requirements:

• You were entitled to file a joint return with your spouse in the year they died (it doesn't matter whether you actually filed a joint return)
• You didn't remarry before the end of the current tax year
• You have a child, stepchild, adopted child, or foster child you can claim as a dependent
• The child lives in the home all year, except for temporary absences
• You paid more than half the cost of keeping up a home for the whole year

Head of Household Status

The head of household filing status often causes confusion among single taxpayers who sometimes file returns erroneously claiming that status. To qualify for head of household status, you typically must be unmarried by the end of the tax year and have a qualifying child. You are not entitled to file as head of household if you qualify as a widow or widower with a dependent child. You must also have paid more than half of the cost of keeping up a home and had the qualifying person living in the home for more than half of the year.

A qualifying person is usually a child but can also be one of your parents. However, other family members who are dependents may qualify.

Head of Household and Married

In some limited situations, you may qualify to file as head of household while you are married. This happens when you are "considered unmarried." You are considered unmarried if:

• You file a separate return from your spouse
• Your spouse has not lived in your home during the last six months of the tax year
• You provided more than half the cost of maintaining your home
• Your home was the primary home of the qualifying person for more than half the year
• You are able to claim the child as a dependent, or you can't claim the child as a dependent only because the noncustodial parent can claim the child

Have More Questions About Your Filing Status? A Tax Lawyer Can Help

If you have questions about which filing status you should use on your federal income tax return, a local tax attorney can help. A tax lawyer is a tax professional who understands the rules for determining eligibility for each filing status and can tell you which one will benefit you the most financially when you have more than one option.