You should file an amended tax return if you need to correct any piece of information that will alter your tax calculations. You can use an amended return to make corrections to your filing status, dependents, income, deductions, or tax credits. For example, if you need to report additional income from a W-2 that arrived after you filed your original return, you’ll need to file an amendment. Similarly, if you need to remove dependents because you were not eligible to claim them, you should file an amendment.

You should not file an amended return if you are only correcting math errors as the IRS computers will check your math and correct any errors in calculation. Math errors are errors in adding or subtracting items on your tax return.

Reasons for filing an amendment include:

• Claiming additional dependedts. 
• Removing dependents you previously claimed.
• Reporting your proper filing status.
• Reporting additional income – from a W2, 1099, or other income statement,
• Making changes in your above the line deductions, standard deductions, or itemized deductions.