Mississippi business tax extension
Mississippi honors the federal extension for Form 83-105, and has its own extension form for a business without one. The federal extension is Form 7004, due for calendar-year corporations and for partnerships and S corporations. In general, an extension gives you more time to file, not more time to pay.
Last updated · From Mississippi's own forms, instructions and laws, cited below
Does Mississippi accept the federal extension?
A federal extension (Form 7004) also extends the Mississippi return. Without a federal extension, file Form 83-180, Application for Automatic Extension.
Mississippi's rules for each business return, as its own instructions and laws state them:
Corporations
- Return
- Form 83-105, Corporate Income and Franchise Tax Return
- Due date
- The 15th day of the 4th month after the tax year ends (April 15 for a calendar year)
- Extension
- A federal extension (Form 7004) also extends the Mississippi return. Without a federal extension, file Form 83-180, Application for Automatic Extension. If tax is due, file Form 83-180 with the payment by the original due date. A federal extension is accepted instead only if no tax is owed on the original due date.
- Extended due date
- The federal extended due date of Form 1120 Calendar-year 2026 returns:
- Payment
- The tax is due by the original due date, even with an extension. To pay with the extension: Form 83-180 with the extension payment.
S corporations and partnerships (Form 84-105)
- Return
- Form 84-105, Pass-Through Entity Tax Return
- Due date
- The 15th day of the 3rd month after the tax year ends (March 15 for a calendar year)
- Extension
- A federal extension (Form 7004) also extends the Mississippi return. Without a federal extension, file Form 83-180, Application for Automatic Extension. If tax is due, file Form 83-180 with the payment by the original due date. A federal extension is accepted instead only if no tax is owed on the original due date.
- Extended due date
- The federal extended due date of Form 1065 Calendar-year 2026 returns:
- Payment
- The tax is due by the original due date, even with an extension. To pay with the extension: Form 83-180 with the extension payment.
Estates and trusts
- Return
- Form 81-110, Mississippi Fiduciary Income Tax Return for Estates and Trusts
- Due date
- The 15th day of the 4th month after the tax year ends (April 15 for a calendar year)
- Extension
- A federal extension carries over: filing Form 7004 with the IRS also extends the Mississippi return, with no separate Mississippi extension form. This holds if no additional tax is owed. Tax owed must be paid with Form 80-106 by the original due date.
- Extended due date
- The federal extended due date of Form 1041 Calendar-year 2026 returns:
- Payment
- The tax is due by the original due date, even with an extension. To pay with the extension: Form 80-106 payment voucher, or online through the Taxpayer Access Point (TAP).
When a due date in Mississippi falls on a weekend or legal holiday, it moves to the next business day. Mississippi's holidays can differ from the federal ones, so a rule not tied to a federal date is given without a computed date.
When is the federal business extension due?
Corporations, S corporations, partnerships, multi-member LLCs, estates and trusts extend their federal return with Form 7004, filed by the return's original due date. The extension is automatic: no reason is needed and the IRS doesn't approve it. We e-file it for a flat $9.95. These are the 2027 dates for calendar-year 2026 returns:
| Return | Who files | File the extension by | Extended to |
|---|---|---|---|
| Form 1065 Partnerships & multi-member LLCs, Form 7004 | 6 months | ||
| Form 1120-S S corporations (and LLCs taxed as S corps), Form 7004 | 6 months | ||
| Form 1120 C corporations (and LLCs taxed as C corps), Form 7004 | 6 months | ||
| Form 1041 Estates & trusts, Form 7004 | 5½ months | ||
| Form 990, 990-EZ, 990-PF Tax-exempt organizations & private foundations, Form 8868 | May 15, 2027 is a Saturday | 6 months |
Federal dates follow the IRS rule: a deadline on a weekend or legal holiday moves to the next business day. A fiscal-year business counts from its own year-end; see the fiscal-year deadline guide.
Tax-exempt organizations extend the 990 series with Form 8868, not Form 7004. Each return needs its own extension, so extending a business return does not extend its owners' personal returns.
Does an extension give more time to pay?
No. A federal extension moves the filing deadline only: tax owed is due by the original due date, and the IRS charges interest and the late-payment penalty on anything paid after it. Mississippi's instructions say the same for its returns: a Mississippi extension doesn't move the payment deadline. More in does an extension give you more time to pay?
Where are Mississippi's forms and instructions?
On the Mississippi Department of Revenue website, which has the current forms, instructions and online services. The rules on this page are summarized from the sources below. We e-file the federal extension; the Mississippi return and any Mississippi extension request go to the state.
Mississippi extension FAQ
Does Mississippi accept the federal business tax extension?
A federal extension (Form 7004) also extends the Mississippi return. Without a federal extension, file Form 83-180, Application for Automatic Extension. If tax is due, file Form 83-180 with the payment by the original due date. A federal extension is accepted instead only if no tax is owed on the original due date.
When is the Mississippi Form 83-105 due?
The 15th day of the 4th month after the tax year ends (April 15 for a calendar year).
Does a Mississippi extension give more time to pay?
No. The tax is due by the original due date, even with an extension. To pay with the extension: Form 83-180 with the extension payment.
Does a Mississippi business still need a federal extension?
Yes, to get more time for its federal return: Form 7004, filed by April 15, 2027 for a calendar-year corporation or March 15, 2027 for a partnership or S corporation. Mississippi honors that federal extension for the state return too.
Sources
- Corporate Income and Franchise Tax Return | Mississippi Department of Revenue, read
- Form 83-100 (Rev. 01/26), 2025 Corporate Income and Franchise Tax Instructions (PDF), read
- Application for Automatic Extension 2025 (Form 83-180, Rev. 10/25) (PDF), read
- Form 84-100 (Rev. 01/26), 2025 Pass-Through Entity Income and Franchise Tax Instructions (PDF), read
- Business Tax Frequently Asked Questions, read
- 2025 Form 81-100 (Rev. 06/25), Fiduciary Income Tax Return Instructions (PDF), read
Filing a federal business extension this season?
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