Filing

• Both you and your spouse must include all of your income on your joint return. You can file your joint return using form 1040, 1040A or 1040EZ. Check the box on line 2 to indicate your joint filing status on forms 1040 and 1040A.
  
  

Joint Responsibility

• On joint returns, both you and your spouse are responsible for the correctness of the income, credits and deductions listed for both you and your return spouse. In addition, both spouses are held responsible for the tax, interest and penalties due as a result of the joint return. If your spouse owes back federal or state debts, your entire refund will be applied to the debt.
  
  

Considerations

• For the purpose of taxation, you and your spouse are considered married if you and your spouse are married and living together, are living in a common law marriage recognized by the state of which you are a resident, are married and living apart but not legally separated or divorced, or are separated but your divorce is not final. If you meet any of the aforementioned criteria on the last day of the tax year, then you are considered married.
  
  

Death

• If your spouse dies during the tax year, you are considered married for the duration of that tax year. You should use the same criteria to determine if your spouse met the requirement to file as you would if he were alive during the tax year. Include all of the decedent's income on your joint return. Sign your name in the signature section of the return. Write "filing as surviving spouse" in the signature area of the decedent. Also, be sure to write the word "deceased" along with the decedent's name and date of death across the top of the IRS Form 1040.
  
  

Exceptions

• If you file married filing separate, then you do not need to include your spouse's income on your income tax return. However, the married filing separate status does not allow as many deductions or credits as filing jointly. Also, you and your spouse must use the same deduction method if you file separately. For instance, if you use the standard deduction method, then so must your spouse and conversely, if you itemize, then so must your spouse.