Filing amended return - was due refund now owe

[PowderStache]

Asking for a friend:
Filed a return last week electronically that had a $100 refund coming.
Realized some income was left off, now owes $50.

When should he file 1040X?  Now to beat the tax deadline, or after the IRS processes the first return?

If now, what size check should he send?  The $50 that he owes, or $150 to repay the refund (that hasn't arrived yet) plus what he owes now?

[dcheesi]

I think generally with a 1040X you send the difference between the original amount and the new. No idea how the timing affects that, unfortunately. I've read/heard that amended returns are handled by a completely separate group, so there's a lot of room for confusion and lack of coordination there.

[SeattleCPA]

To keep things easy, I'd probably just wait to hear from IRS.

When you hear, they will bill you for the $150.

They may also ding you with small-ish penalty (sort of an 8%-ish interest rate)... or the big 25% penalty. Either way, the penalty won't be THAT big. And you'll let them (the IRS) handle the accounting and the amending.

[secondcor521]

Has your friend read these?

https://www.irs.gov/faqs/irs-procedures/amended-returns-form-1040x/amended-returns-form-1040x

https://www.irs.gov/pub/irs-pdf/i1040x.pdf

When to file is on page 3 of the second link.

How big of a check to send is probably covered in the instructions for line 20 of the Form 1040X, which is on page 15 of the second link.