If you need more time to file your Mississippi return, and you will receive a refund or will not owe any additional tax, Mississippi will allow you the same time that is allowed by your federal extension.
If you expect to owe additional tax by the April 15 due date and you need more time to file your Mississippi income tax return, you must pay all of your state tax due with Mississippi Form 80-180 by April 15. The extension of time to file does not extend the due date for payment of your Mississippi income tax.
More time to file does not mean more time to pay your taxes.
You will owe interest and penalty from April 15 to date of payment. The interest rate is due at 8/10th of one percent (1%) per month, and the penalty rate is one-half of one percent (.5%) per month or part of a month from April 15 until the date the final payment is received. Late payment penalty will accrue to a maximum of twenty-five percent (25%). Late payment penalty and interest apply to any unpaid tax after April 15.
The penalty imposed for failure to file a return is five percent (5%) per month not to exceed twenty-five (25%) in the aggregate. The penalty imposed for failure to file is based on the additional amount of tax due. Such failure to file a return penalty shall not be less than $100.