Regarding applying a refund. Q1 est. tax is due April 15, what if the IRS doesn't process the refund until after April 15 despite on-time filing? Is the est payment late?
I want to apply the refund from last year (2018) to 2019 Q1 Estimated Tax Payment. But I was unclear about the timing. Is the payment applied when you file or when the IRS processes the refund.
