How to Amend a Return to Increase Deductions & Claim Dependents

Visit the Internal Revenue Service website at IRS.gov and obtain Form 1040X, which is the Amended U.S. Individual Income Tax Return, Form 1040X instructions, and Form 1040 Instructions.

Check the box that represents the tax year you are amending on Form 1040X.

Enter your name, address, Social Security number and phone number in the fields on the top portion of the form. If you filed your previous tax return with your spouse, enter your spouse's information.

Check the box that relates to your filing status.

Complete "Column A" in the Income and Deductions, Tax Liability and Payments sections using the information from your previously filed income tax return.

Multiply the number of dependents not claimed on your previous tax return by the current year exemption amount. Enter this number in "Column B" of the line labeled "Exemptions." For example, if you are claiming two additional dependents for the 2012 tax year, multiply two by $3,700. Enter $7,400 in "Column B." The IRS adjusts the amount you can deduct for an exemption each year, so refer to the form's instructions for the correct amount.

Perform the remaining calculations in the "Income and Deductions" section to determine your taxable income.

Compare the amount in Column C of the line labeled "Taxable Income" to the tax charts on the Form 1040 instructions to determine your tax. For example, if the amount in Column C is $41,500, find the chart labeled "41,000." Locate your income and follow the line across until you reach your filing status. The amount listed is your tax. Enter this amount in "Column C" of the line labeled "Tax." Subtract "Column C" from "Column A" and enter the amount in "Column B."

Perform the remaining calculations in the "Tax Liability" section to determine your total tax.

Complete the lines labeled "Federal Income Tax Withheld" and "Estimated Tax Payments" using the information from your previous income tax return.

Calculate your Earned Income Credit using the chart on Form 1040 Instructions, if applicable. Enter the new amount in "Column C" of the line labeled "Earned Income Credit." Subtract the amount in "Column A" from "Column C" and enter the amount in "Column B." You must also complete Schedule EIC to claim the credit.

Establish whether you qualify for any additional tax credits. These credits can include the Making Work Pay Credit, Additional Child Tax Credit, Qualified Adoption Expenses and Education Credit. Complete the required form and enter the amount of your credit in "Column C" of the line labeled "Refundable Credits." Subtract "Column A" from "Column C" and enter the difference in "Column B."

Complete the "Refund or Amount You Owe" section to determine the amount of your refund.

Complete the section labeled "Exemptions" on the second page of Form 1040X. The first part of the section requires you to account for each dependent you are claiming on the amended return.

Enter the name, Social Security number and relationship of each additional dependent you are claiming on the amended return. You are not required to enter the information of dependents claimed on your previously filed tax return. Refer to the Form 1040X instructions to determine whether the dependent qualifies for the Child Tax Credit.

Determine whether you would like to contribute to the Presidential Election Campaign Fund.

Enter the reason you are filing the amended in "Part III" of Form 1040X. If you are filing the form to claim additional dependents and deduction, simply state that you overlooked a dependent on your original tax return.

Sign and date the Form 1040X. If you are married, have your spouse sign the form.

Attach any additional forms and schedules and mail the return to the IRS center that corresponds with your area. The mailing address is listed on the Form 1040X instructions.