Is mailing 2017 taxes and efiling 2018 taxes at the same time allowed? I'll be using some data from 2017 (such as federal refund) in 2018 filing.

[Rachel_W · Accepted solution]

Yes, mailing your 2017 taxes and e-filing your 2018 taxes at the same time is allowed.

In order to e-file your 2018 Tax Return, you will need to enter -0- for your 2017 AGI since that return hasn't been processed by the IRS yet.

[shash]

Thank you.