If I efile a request for extension of federal tax return deadline, may I also efile the final tax return?

[PaulaM · Accepted solution]

Yes, you can efile the extension and the final tax return within the extension window. See reference link below.

IRS FAQ: Efile and Extensions

[xmasbaby0 · Accepted solution]

That is correct; you can e-file the extension request and the final tax return--provided you do both of those things within the deadlines.  You have to request an extension before the actual April filing deadline for the upcoming 2019 tax year and you have to e-file the tax return no later than the mid-October e-filing deadline.  An extension does NOT give you extra time to pay your tax due.  You have to PAY your estimated 2019 tax due by the April filing deadline.

And of course, it is way too late to ask for an extension for a 2018 tax return,