Mississippi Tax Extension: Forms, Filing, and Late Payment Costs

A Mississippi tax extension is automatic if you’ve filed a federal extension on IRS Form 4868, which pushes your state filing deadline from April 15 to October 15, 2026.¹ No separate state application is required in that case. If you don’t have a federal extension, or you owe Mississippi tax, you’ll need to file Form 80-106 and send payment by April 15. Interest and penalties start accruing immediately on any unpaid balance, extension or not.

The Two Deadlines That Matter

Mississippi individual income tax returns for the 2025 tax year are due April 15, 2026.¹ With an extension, you have until October 15, 2026 to file.²

Keep the two deadlines separate in your head. The October date covers paperwork. Any tax you owe is still due April 15, and the state charges interest and penalties on balances not paid by that date. If you expect a refund, or you owe nothing, the extension is genuinely painless. If you owe money, the extension buys you time to file but not time to pay.

When Your Federal Extension Covers Mississippi

If you’ve filed IRS Form 4868, Mississippi automatically grants you a matching extension. You don’t submit any additional state paperwork to get the extra time.¹

When you eventually file your Mississippi return, attach a copy of your federal Form 4868.¹ This step gets overlooked. The extension is automatic, but the state wants proof of the federal extension on file with your completed return, and leaving it out can trigger follow-up from the Department of Revenue.

When You Need a Mississippi Extension Form

You’ll need to file a Mississippi-specific form in two situations: you don’t have a federal extension, or you owe state tax and need to submit payment. The form depends on who’s filing.

Individuals and fiduciaries use Form 80-106, the Individual/Fiduciary Income Tax Payment Voucher. It covers resident returns (Form 80-105), nonresident returns (Form 80-205), and fiduciary returns (Form 81-110).³

Business entities, including C corporations, S corporations, partnerships, LLCs, LLPs, and electing pass-through entities, use Form 83-180, the Application for Automatic Extension.⁴

Both forms ask for your identifying numbers (SSN or ITIN for individuals, FEIN for businesses and trusts).³ You’ll estimate your total tax liability for the year, subtract withholding and any estimated payments already made, and calculate the balance due. Make the estimate reasonably accurate. A wildly low number could undermine your extension if the Department of Revenue later finds you didn’t make a good-faith effort to pay.

How to File and Pay

Online Through TAP

The Mississippi Taxpayer Access Point (TAP) handles extension payments even if you plan to file your return on paper.⁵ Log in, find your individual income tax account, and select the option to make an extension payment. Save the electronic confirmation. That receipt is your proof of timely payment if a question comes up later.

By Mail

If you’re mailing Form 80-106 as a standalone extension payment without a completed return, send it to:

Department of Revenue
P.O. Box 23192
Jackson, MS 39225-3192³

If you’re mailing the voucher along with a completed return, the address is different: P.O. Box 23050, Jackson, MS 39225-3050.³ Include a check or money order for the estimated balance. Use a mailing method with tracking so you have proof the state received your documents before April 15.

What Late Payment Costs

Mississippi charges interest at 0.5% per month on unpaid tax balances for taxes assessed on or after January 1, 2019.⁶ That works out to 6% a year. On a $2,000 balance, you’d owe about $10 in interest for every month unpaid, roughly $60 by the time October 15 arrives.

A separate late payment penalty of 0.5% per month also applies, capping at 25% of the unpaid tax.⁷ Combined with interest, letting a balance sit for the full six-month extension adds roughly 6% to what you owe.

Skipping the extension entirely is far worse. The failure-to-file penalty is 5% per month, up to 25%, with a $100 minimum.⁶ That’s ten times the late payment rate. Filing an extension and paying what you can by April 15, even if it’s partial, is always better than doing nothing. Any payment reduces the principal that interest and penalties are calculated against.

If You Can’t Pay the Full Balance

Mississippi offers installment agreements for some taxpayers who file on time but can’t pay. You may qualify if your tax liability is between $75 and $3,000. For balances above $3,000, you can request an installment plan if you’ve already set up a federal installment agreement with the IRS for the same tax year.⁶

Conditions apply. You must have filed all required returns, paid all taxes owed, and not entered into an installment agreement in the prior five years. If approved, balances under $3,000 must be paid within 12 months. Larger balances under the IRS-linked option can run up to 60 months.⁶ Interest and penalties keep accruing during the installment period, so paying it off faster costs less.

Military and Disaster Situations

Because Mississippi automatically recognizes federal extensions, service members who receive extra time from the IRS get the same treatment at the state level.⁸ That covers the automatic two-month extension for taxpayers living and working abroad and the 180-day combat zone extension, which delays both filing and payment deadlines. Attach documentation of your deployment status when you file your Mississippi return.

When a federal disaster is declared in Mississippi, the Department of Revenue typically mirrors IRS relief, postponing filing and payment deadlines automatically for affected taxpayers. If you’re in a disaster area and receive a penalty notice, call the Department of Revenue at (601) 923-7700 to request abatement.⁹ The same number works if your records are in the disaster area even though you live elsewhere. Disaster relief doesn’t automatically cover every tax type, so confirm which deadlines have been extended for your situation.

1
Mississippi Department of Revenue. Individual Income Tax Frequently Asked Questions
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Internal Revenue Service. If You Need More Time to File, Request an Extension
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Mississippi Department of Revenue. Mississippi Individual/Fiduciary Income Tax Voucher
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Mississippi Department of Revenue. Mississippi Application for Automatic Extension 2025
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Mississippi Department of Revenue. Make Online Tax Payments
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Justia Law. Mississippi Code Title 27 Chapter 7 – Delinquent Taxes; Failure to File Return
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Justia Law. Mississippi Code Title 27 Chapter 7 – Additional Taxes or Refunds
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Justia Law. Mississippi Code Title 27 Chapter 7 – Extension of Time to File Return
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Mississippi Department of Revenue. Relief for Victims of Winter Storm Fern in Mississippi