How do I file for a tax extension in 2018 if I haven't finish / submit my 2017 tax return?

[RenataS]

You need to estimate your tax liability amount when filing extension. 

[tphi96]

Thank you.  What do I put in the AGI question when filing my extension as I haven't submit my 2017 tax return yet?

[RenataS]

You can estimate that amount too based on income documents you have for 2017.

[tphi96]

Thanks for the fast response.  I input my estimate amount and submit the extension.  IRS rejected my extension application.

[RenataS]

What is the reject code?   it should be in the rejection email.

[RenataS]

Try entering zero for last year AGI

[tphi96]

I tried to reply with the reject code but it's not allowed.  I will submit extension again with AGI $0.  Thanks