An amended tax return allows an individual to make changes to a filed tax return. The Internal Revenue Service allows filers to submit amended returns to change the filing status, fix the income, or add and subtract deductions or credits on filed tax returns.
The IRS detects mathematical errors and correct them automatically. There is no need to file an amended return for such errors. The IRS does not require an amended return for missing forms such as a W-2, which reports the income earned during the tax year. A request from the IRS is sent out for the missing documents.