Depending on your tax situation, there are several ways that you can sign your federal income tax return.

Method   Description   Best to use if:  
Self-Select PIN The PIN is any five numbers (except all zeros) the taxpayer chooses to enter as their electronic signature.

A PIN is needed for each taxpayer if filing through an Electronic Return Originator (ERO) or with Tax Preparation Software. The taxpayer's date of birth and prior year's adjusted gross income (AGI) from the original return must also be entered for authentication.
You are over the age of sixteen and have filed a tax return before.

All filing statuses

You have access to last year’s return. You need last year’s AGI info to sign with this method.

Enter zero (0) if you have never filed a tax return or did not need to file a tax return last year.

If your filing status changes because you got married, then each taxpayer must use their individual original total AGI amount from their respective prior year's tax returns.

If your filing status is changing this year due to divorce or separation, then each taxpayer must use the same original total AGI amount from the prior year's joint return.

If you filed an amended tax return last year, use the AGI amount from the originally filed return.
Have your Tax Professional sign your return for you. If you hired a preparer do your taxes for you, you must sign an IRS e-file Signature Authorization so your practitioner can e-file your return. Taxpayers that are having a tax professional prepare and e-file a return for them.