When self-preparing your taxes and filing electronically, you must sign and validate your electronic tax return by entering your prior-year Adjusted Gross Income (AGI) or your prior-year Self-Select PIN.
Generally, tax software automatically enters the information for returning customers. If you are using a software product for the first time, you may have to enter the information yourself.
If you have an Identity Protection (IP) PIN (via a CP01A or the Get an IP PIN Tool), you must enter it when prompted by your software. It will serve to verify your identity instead of your prior-year AGI or prior-year Self Select PIN. You can opt into the IP PIN program through the online tool.
You should always retain a copy of your tax return.
If you do not have a copy of your tax return, you can get your AGI from one of the IRS self-service tools: