You are considered unmarried for the whole year if, on the last day of your tax year, you are unmarried or legally separated from your spouse under a divorce or a separate maintenance decree. State law governs whether you are married or legally separated under a divorce or separate maintenance decree.

If you are divorced under a final decree by the last day of the year, you are considered unmarried for the whole year.

If you obtain a divorce in one year for the sole purpose of filing tax returns as unmarried individuals, and at the time of divorce you intended to and did remarry each other in the next tax year, you and your spouse must file as married individuals.

If you obtain a court decree of annulment, which holds that no valid marriage ever existed, you are considered unmarried even if you filed joint returns for earlier years. You must file amended returns (Form 1040X, Amended U.S. Individual Income Tax Return) claiming single or head of household status for all tax years affected by the annulment that are not closed by the statute of limitations for filing a tax return. The statute of limitations generally does not expire until 3 years after your original return was filed.

If you are considered unmarried, you may be able to file as a head of household or as a qualifying widow(er) with a dependent child. See Head of Household and Qualifying Widow(er) With Dependent Child to see if you qualify.

If you are considered married for the whole year, you and your spouse can file a joint return, or you can file separate returns.

You are considered married for the whole year if on the last day of your tax year you and your spouse meet any one of the following tests.

If your spouse died during the year, you are considered married for the whole year for filing status purposes.

If you did not remarry before the end of the tax year, you can file a joint return for yourself and your deceased spouse. For the next 2 years, you may be entitled to the special benefits described later under Qualifying Widow(er) With Dependent Child.

If you remarried before the end of the tax year, you can file a joint return with your new spouse. Your deceased spouse's filing status is married filing separately for that year.

If you live apart from your spouse and meet certain tests, you may be considered unmarried. If this applies to you, you can file as head of household even though you are not divorced or legally separated. If you qualify to file as head of household instead of as married filing separately, your standard deduction will be higher. Also, your tax may be lower, and you may be able to claim the earned income credit. See Head of Household, later.

You can file Form 1040EZ (if you have no dependents, are under 65 and not blind, and meet other requirements), Form 1040A, or Form 1040. If you file Form 1040A or Form 1040, show your filing status as single by checking the box on line 1. Use the Single column of the Tax Table or Schedule X of the Tax Rate Schedules to figure your tax.

If you file as married filing jointly, you can use Form 1040 or Form 1040A. If you have no dependents, are under 65 and not blind, and meet other requirements, you can file Form 1040EZ. If you file Form 1040 or Form 1040A, show this filing status by checking the box on line 2. Use the Married filing jointly column of the Tax Table or Schedule Y–1 of the Tax Rate Schedules to figure your tax.

If your spouse died during the year, you are considered married for the whole year and can choose married filing jointly as your filing status. See Spouse died, earlier, for more information.

If you are divorced under a final decree by the last day of the year, you are considered unmarried for the whole year and you cannot choose married filing jointly as your filing status.

Both of you must use the same accounting period, but you can use different accounting methods. See Accounting Periods and Accounting Methods in chapter 1.

Both of you may be held responsible, jointly and individually, for the tax and any interest or penalty due on your joint return. One spouse may be held responsible for all the tax due even if all the income was earned by the other spouse.

You may be held jointly and individually responsible for any tax, interest, and penalties due on a joint return filed before your divorce. This responsibility may apply even if your divorce decree states that your former spouse will be responsible for any amounts due on previously filed joint returns.

In some cases, one spouse may be relieved of joint liability for tax, interest, and penalties on a joint return for items of the other spouse that were incorrectly reported on the joint return. You can ask for relief no matter how small the liability.

There are three types of relief available.

You must file Form 8857, Request for Innocent Spouse Relief, to request any of these kinds of relief. Publication 971, Innocent Spouse Relief, explains these kinds of relief and who may qualify for them.

For a return to be considered a joint return, both husband and wife must generally sign the return. If your spouse died before signing the return, see Signing the return in chapter 4.

If your spouse is away from home, you should prepare the return, sign it, and send it to your spouse to sign so that it can be filed on time.

If your spouse cannot sign because of disease or injury and tells you to sign, you can sign your spouse's name in the proper space on the return followed by the words “By (your name), Husband (or Wife).” Be sure to also sign in the space provided for your signature. Attach a dated statement, signed by you, to the return. The statement should include the form number of the return you are filing, the tax year, the reason your spouse cannot sign, and a statement that your spouse has agreed to your signing for him or her.

If you are the guardian of your spouse who is mentally incompetent, you can sign the return for your spouse as guardian.

If your spouse is unable to sign the return because he or she is serving in a combat zone (such as the Persian Gulf Area, Yugoslavia, or Afghanistan), or a qualified hazardous duty area (Bosnia and Herzegovina, Croatia, and Macedonia), and you do not have a power of attorney or other statement, you can sign for your spouse. Attach a signed statement to your return that explains that your spouse is serving in a combat zone. For more information on special tax rules for persons who are serving in a combat zone, or who are in missing status as a result of serving in a combat zone, get Publication 3, Armed Forces' Tax Guide.

If your spouse cannot sign the joint return for any other reason, you can sign for your spouse only if you are given a valid power of attorney (a legal document giving you permission to act for your spouse). Attach the power of attorney (or a copy of it) to your tax return. You can use Form 2848, Power of Attorney and Declaration of Representative.

A joint return generally cannot be filed if either spouse is a nonresident alien at any time during the tax year. However, if one spouse was a nonresident alien or dual-status alien who was married to a U.S. citizen or resident at the end of the year, the spouses can choose to file a joint return. If you do file a joint return, you and your spouse are both treated as U.S. residents for the entire tax year. For information on this choice, see chapter 1 of Publication 519.

If you file a separate return, you generally report only your own income, exemptions, credits, and deductions. You can claim an exemption for your spouse if your spouse had no gross income and was not a dependent of another person. However, if your spouse had any gross income, or was the dependent of someone else, you cannot claim an exemption for him or her on your separate return.

You may not be able to deduct all or part of your contributions to a traditional IRA if you or your spouse were covered by an employee retirement plan at work during the year. Your deduction is reduced or eliminated if your income is more than a certain amount. This amount is lower for married individuals who file separately and lived together at any time during the year. For more information, see How Much Can I Deduct in chapter 18.

If you actively participated in a passive rental real estate activity that produced a loss, you generally can deduct the loss from your nonpassive income, up to $25,000. This is called a special allowance. However, married persons filing separate returns who lived together at any time during the year cannot claim this special allowance. Married persons filing separate returns who lived apart at all times during the year are each allowed a $12,500 maximum special allowance for losses from passive real estate activities. See Limits on Rental Losses in chapter 10.

If you live in Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington, or Wisconsin and file separately, your income may be considered separate income or community income for income tax purposes. See Publication 555.

A personal representative for a decedent can change from a joint return elected by the surviving spouse to a separate return for the decedent. The personal representative has 1 year from the due date of the return to make the change. See chapter 4 for more information on filing a return for a decedent.

A child may qualify you to file as head of household even if the child has been kidnapped. For more information, see Publication 501.

If you file as head of household, you can use either Form 1040A or Form 1040. Indicate your choice of this filing status by checking the box on line 4 of either form. Use the Head of a household column of the Tax Table or Schedule Z of the Tax Rate Schedules to figure your tax.

You are considered unmarried for head of household purposes if your spouse was a nonresident alien at any time during the year and you do not choose to treat your nonresident spouse as a resident alien. However, your spouse is not a qualifying person for head of household purposes. You must have another qualifying person and meet the other tests to be eligible to file as a head of household.

Even if you are considered unmarried for head of household purposes because you are married to a nonresident alien, you are still considered married for purposes of the earned income credit (unless you meet the five tests listed earlier). You are not entitled to the credit unless you file a joint return with your spouse and meet other qualifications. See chapter 38 for more information.

You are considered married if you choose to treat your spouse as a resident alien.

Include in the cost of upkeep expenses such as rent, mortgage interest, real estate taxes, insurance on the home, repairs, utilities, and food eaten in the home.

Do not include in the cost of upkeep expenses such as clothing, education, medical treatment, vacations, life insurance, or transportation. Also, do not include the rental value of a home you own or the value of your services or those of a member of your household.

Generally, the qualifying person must live with you for more than half of the year.

You may be eligible to file as head of household even if the parent for whom you can claim an exemption does not live with you. You must pay more than half the cost of keeping up a home that was the main home for the entire year for your father or mother. You are keeping up a main home for your father or mother if you pay more than half the cost of keeping your parent in a rest home or home for the elderly.

You and your qualifying person are considered to live together even if one or both of you are temporarily absent from your home due to special circumstances such as illness, education, business, vacation, or military service. It must be reasonable to assume that the absent person will return to the household after the temporary absence. You must continue to keep up the home during the absence.

You may be eligible to file as head of household if the individual who qualifies you for this filing status is born or dies during the year. You must have provided more than half of the cost of keeping up a home that was the individual's main home for more than half the year or, if less, the period during which the individual lived.

If you file as qualifying widow(er) with dependent child, you can use either Form 1040A or Form 1040. Indicate your filing status by checking the box on line 5 of either form. Use the Married filing jointly column of the Tax Table or Schedule Y–1 of the Tax Rate Schedules to figure your tax.

You are eligible to file your 2003 return as a qualifying widow(er) with dependent child if you meet all of the following tests.

As mentioned earlier, this filing status is only available for 2 years following the year of death of your spouse.

You may be eligible to file as a qualifying widow(er) with dependent child if the child who qualifies you for this filing status is born or dies during the year. You must have provided more than half of the cost of keeping up a home that was the child's main home during the entire part of the year he or she was alive.