I'm going to owe quite a bit due to underestimating my quarterly payments.
I've filed an extension due to a pending K-1.
In order to minimize penalties, I plan to pay as much as I can April 15 with my 4868 extension. Can I send payments in May and June using 1040-V or select the "Tax Return or Notice" option in Direct Pay to make additional payments for 2018? If I select quarterly payments, it defaults to 2019.
Thanks!
