You must pay the total tax due when you file the extension. BUT you haven't prepared the return, so what the heck?... Here's a tool that I've used to success in preparing estimated taxes all year long. It's made available for free from Atlantic Union Bank. Visit the site at [website removed] and look for its Federal Income Tax Calculator. I used it recently in January 2023 and wound up getting an $884 refund, which is exactly the way I like it: Tiny refund, no tax owed since it was already paid in, no penalty.
