MS 2026 Tax Filing Deadline: Key Dates You Must Know

Jordan Hartwell

Published: February 5, 2026 8:14 PM ET

Tax deadlines are crucial for taxpayers, and understanding the key dates can help avoid stress as the tax season approaches. For 2026, Mississippi residents need to be aware of these important tax filing dates.

MS 2026 Tax Filing Deadline: Key Dates You Must Know

Filing and Payment Deadline

The deadline to file and pay federal and state taxes in Mississippi for the year 2025 is set for Wednesday, April 15, 2026. This date is crucial according to the Internal Revenue Service (IRS) and the Mississippi Department of Revenue.

Mail Filings

If you are filing your tax return via mail, it is essential to ensure that your envelope is correctly addressed and postmarked by the due date. This will determine if your return is considered “on time” by the IRS.

Extensions and Disaster Relief

In some cases, taxpayers may need more time to organize their documents. The IRS allows individuals to request a six-month tax extension by filing Form 4868 by the original due date. However, it’s important to note that this extension applies only to filing, not to payment.

Additionally, following severe storms and disasters in March 2025, certain counties in Mississippi were granted tax relief. Residents in affected areas, including Calhoun, Carroll, and several others, had an extended deadline of November 3, 2025, for filing their returns and tax payments.

Consequences of Not Filing

Failing to file your tax return on time can lead to significant penalties. The IRS imposes a penalty of 5% of the taxes due for each month the return is late, accruing up to a maximum of 25%. If your return is more than 60 days overdue, the minimum penalty increases to $525 or 100% of the unpaid tax, whichever is less. Interest on these penalties may also accumulate.

Should you fail to file altogether, the IRS can file a substitute return on your behalf, potentially leading to an unpaid tax bill and further collection actions. Repeated failures to file may result in additional enforcement measures, including criminal prosecution.

Filing Deadline: April 15, 2026, for federal and state taxes.
Disaster Relief Deadline: November 3, 2025, for certain counties.
Extension Request: File Form 4868 by the original deadline for a six-month extension.

Being proactive and organized is key to successfully navigating the tax season in Mississippi. Stay informed to avoid penalties and ensure timely filing of your taxes.