Interest generally accrues on the unpaid balance of your tax starting from the due date of the tax return. An extension to file doesn't extend the time payment is due. If the return in question was for tax year 2023, interest has been accruing since April 15, 2024.
By filing your return on time, including extensions, you can avoid the penalty for late filing. Filing timely does not stop interest from accruing on any unpaid balance. In addition to interest, you may also be liable for a late payment penalty, which is .5% per month on the unpaid balance. See here for more information about the late payment penalty.
The interest rate for unpaid taxes is subject to change quarterly. You would owe interest at the prevailing rate for each quarter in which you have a balance due. See here for the interest rates.
You can make a payment toward your estimated tax due at any time. Interest will stop accruing on the amount paid as of the date it was received. The easiest way to make payments is on the IRS website at Make a Payment. Make sure you are applying the payment to the correct year.
@An2425
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
