The January 15, 2024 date was for the final 2024 1040-ES payment. There is no need to submit any 2025 estimates until the first one is due on April 15, 2025. And like someone previously stated, it is best to use the online method to make the estimated payments, so no IRS form nor envelope is even needed. But if you insist on mailing the estimates, by April 15 the final version of 1040-ES will surely be available.
