Form 1040X is the amended return.
Assuming the original (but incomplete) return was processed, and the Service has not made any changes to what you filed (you would have received a notice if we did.) You were self employed in 2013, and the Form 1099-MISC is the record of your payment.
Do not include a copy of your original return with your amended return.
Filing 1040X for an Amended Return
Be sure your input your current address, and check the appropriate tax year and filing status boxes.
Page 1, Column A is where you input the figures on the original return (see my assumption statement above).
Page 1, Column C is the finished product after your corrections.
Page 1, Column B is where you show the math. Negative figures are in (parentheses). You should see changes to AGI on Line 1, Taxable Income and Tax on Lines 5 and 6. Your self employment tax will be on Line 9.
Schedule C (http://www.irs.gov/uac/Schedule-C-(Form-1040),-Profit-or-Loss-From-Business) is where you report your income and expenses from the business, and determine your profit or loss. This schedule is attached to Form 1040X.
Schedule SE (http://www.irs.gov/uac/Schedule-SE-(Form-1040),-Self-Employment-Tax) is where you compute your Self Employment tax liability (Line 9 on the 1040X), and is also attached to your Form 1040X.
Page 2, Part III is your written explanation of the changes. Keep this simple: “Adding Schedule C and Schedule SE”. This assumes no other supporting forms or schedules are changing. You must sign and date the return.
Mailing Form 1040X to IRS
After you mail the return, please allow 12 weeks for process. If the return indicates a balance due, pay the amount due when you file. When the claim is processed, the Service will send a notice that explains the change. If the return shows a refund, you will receive a paper check. Four weeks after you mail the return(s), you can track the progress here: (http://www.irs.gov/Filing/Individuals/Amended-Returns-(Form-1040-X)/Wheres-My-Amended-Return-1)
Contacting IRS about Amended Return
If you do not receive a notice after 12 weeks, call customer service at 1-800-829-8374 M – F 7am – 7pm, and let the representative know you are checking on your Form 1040X and you have already checked the automated system. You may have to amend your state income tax return as well.