I filed without realizing I may not have had to due to the worksheet Notice 703 on form SSA-1099-SM. Can I cancel or must I amend?

[DoninGA]

Did you enter the Social Security benefits reported on the SSA-1099 on the tax return that you filed?

[garyodan]

No

[DoninGA · Accepted solution]

If the IRS rejects your tax return then you can add the Social Security benefits received and reported on the SSA-1099 to the 2017 tax return and e-file again.

If the IRS accepts your tax return then you will need to wait for the tax refund to be received or the taxes paid to be processed by the IRS.  Then you will have to amend the 2017 tax return to add the SS benefits to the 2017 tax return.  The amended tax return, Form 1040X, can only be printed and mailed by you to the IRS, it cannot be e-filed.  The IRS will take from 3 to 4 months to process the amended tax return.

See this TurboTax support FAQ for amending a tax return - https://ttlc.intuit.com/questions/1894381-how-to-amend-change-or-correct-a-return-you-already-filed