Income Limits

• A single taxpayer under the age of 65 must file a tax return if his gross income surpasses $9,350. A single taxpayer who is older than 65 must file an income tax return if his income is more than $10,750. Married couples filing jointly who are both under 65 must file a tax return if their gross income surpasses $18,700. Married couples filing jointly who are both over 65 must file a tax return if their income is over $20,900. Married couples filing jointly where one spouse is 65 or older must file a return if their combined gross income surpasses $19,800. Married couples filing separately must file a return at any age if their individual income surpasses $3,650. A taxpayer filing for head of household status who is under 65 must file a return if her gross income surpasses $12,050, head of household claimants over 65 must file a return when their income reaches $16,150. A widow who is under 65 with qualified dependents must file a return if her income surpasses $15,050; widows older than 65 must file a return if their income reaches $16,150 as of May 2011.
  
  

Taxpaying Dependents

• Taxpayers who are single or married, but qualify as a dependent for another taxpayer, must still file a tax return if they surpass certain income limits regarding unearned income, earned income or gross income. Unearned income includes taxable interest, unemployment compensation, pensions and annuities or distributions form a trust fund. Earned income includes taxable income from wages and scholarship or fellowship grants. The sum of your earned and unearned income equals your gross income.
  
  Single dependents who are 65 or older or legally blind must file a return if their unearned income surpasses $2,350 ($3,750 if both 65 or older and blind), their earned income surpasses $7,100 ($8,500 if over 65 and blind), or if your gross income is greater than the larger of $2,350 (up to $5,400) or earned income plus $1,700 ($3,100 if over 65 and blind) as of May 2011.
  
  Married dependents who are 65 or older or blind must file a tax return if their unearned income is over $2,050 ($3,150 if over 65 and blind), earned income surpassed $6,800 ($7,900 if over 65 and blind), or gross income is greater than the larger of $2,050 ($3,150 if over 65 and blind) or earned income plus $1,400 ($2,500 if over 65 and blind).
  
  Single and married dependents who are under 65 and not legally blind must file a return if their unearned income surpasses $950, earned income surpasses $5,700 or gross income was more than $950 or earned income (up to $5,400) plus $300.
  
  

Other Filing Requirements

• A self-employed taxpayer must file a Schedule SE tax return if she earns at least $400 and pay self-employment taxes. If you work for a church and receive at least $108.28 or more in income, you must also file a Schedule SE and pay self-employment tax. Businesses structured as partnerships must file a tax return unless it neither receives a gross income nor pays any expenses treated as a deduction or credit for federal tax purposes. Corporations must file a tax return whether it receives a gross income or not.
  
  

Considerations

• Even if you aren't required to file a return because you fail to meet income filing requirements, it may be wise to file a tax return anyway because you could be leaving money on the table. If you have any federal income or earned income credit, you may still qualify for special tax credits, such as the earned income credit. Even if you have little to no earned income, you may qualify for other tax credits such as the child tax credit if you have qualifying dependents.