Strangely I can't find the answer to this question for a client. He is still gathering documentation and won't be able to file by the extended deadline. So, he is proposing sending in an estimated payment to cover the anticipated taxes and stop any penalties.
But what impact does this have on late filing penalties? He will be filing late. Will the penalties be charged on the balance from July 15 (normally April 15) through the October 15 payment?
Or will it be on the amount reported on the returns when filed, which would theoretically be a refund based on the estimated payment being made by the extended filing deadline?
As an extreme example, if he was to make an estimated payment in December, and then file the returns, they would show no balance when he files, but there's no way he wouldn't have a late filing penalty.
I suspect, to avoid late filing, payment needs to be made by the extended deadline (if valid extension) even if the returns aren't filed, but I can't seem to confirm.... thus TPT. TIA