I generally check the option to have the IRS calculate the penalty instead of PS. Probably 90% of my clients that owe, forget that I gave them that information, so starting a few years ago I make a notation on the client copy that the IRS may bill them for ES tax penalty. 2024 was was bonus year for TN, returns were not due until 11/03/2025 and no penalty or interest due to diaster decleration.