Mississippi tax deadlines in 2026: filing dates and estimated payments
Deadlines that fall in calendar 2026: the 2025 return and the 2026 estimated payments. Different year? See Mississippi 2025 →
Mississippi deadlines in 2026
| 2025 individual return due | April 15, 2026 |
|---|---|
| Extended filing deadline | October 15, 2026 |
| Payment due | April 15, 2026, extension or not |
| Final 2025 estimated payment | January 15, 2026 |
| 2026 estimated payments | April 15, 2026 · June 15, 2026 · September 15, 2026 · January 15, 2027 |
Conforms to the federal deadline.
Mississippi estimated tax payments in 2026
You must make estimated payments if you do not have at least 80% of your annual Mississippi income tax liability prepaid through withholding and your annual tax liability exceeds $200.
| Q1 (2026 tax year) | April 15, 2026 |
|---|---|
| Q2 (2026 tax year) | June 15, 2026 |
| Q3 (2026 tax year) | September 15, 2026 |
| Q4 (2026 tax year) | January 15, 2027 |
| Voucher | Form 80-106 |
| Underpayment safe harbor | Estimated payments plus withholding must be at least 80% of the annual income tax liability; Mississippi publishes no prior-year percentage alternative. |
| Pay online | tap.dor.ms.gov |
Underpayment or late payment carries interest of 1/2% per month from the due date until paid. Farmers and fishermen owe no interest if 80% of the estimate is paid by the 15th day of the first month after year end or the return is filed and paid by the first day of the third month after year end. Form 80-106 is also the return and extension payment voucher.
Source: dor.ms.gov, read September 3, 2026. “April 15th, June 15th, September 15th, and January 15th.”
All 51 jurisdictions in one table: state estimated tax payment dates for 2026.
Mississippi extensions
Every state's rule in one table: which states accept the federal extension in 2026.
| Does Mississippi accept the federal extension? | Yes. A federal extension is honored; no state form. |
|---|---|
| Original due date | April 15, 2026 |
| Extended due date | October 15, 2026 |
| Payment | Still due April 15, 2026. The extension is to file, not to pay. The extension is for filing only; tax due should be paid by April 15, 2026 to avoid penalty and interest. |
| How to get it | File federal Form 4868 and attach a copy to the Mississippi return; if you owe, remit payment with Form 80-106 voucher by April 15. |
Form 80-106 is a payment voucher, not an extension request.
Source: dor.ms.gov, read September 3, 2026. “If you receive an extension of time to file your federal income tax return, you are automatically allowed an extension of time to file your Mississippi income tax return.”
Federal deadlines in 2026
| 2025 Form 1040 | April 15, 2026 · extension October 15, 2026 |
|---|---|
| 2025 S-corp (1120-S) & partnership (1065) | March 16, 2026 |
| 2025 C-corp (Form 1120) | April 15, 2026 |
| 2026 federal estimated payments (1040-ES) | April 15, 2026 · June 15, 2026 · September 15, 2026 · January 15, 2027 |
Source: IRS Publication 509 and Form 1040-ES instructions, irs.gov.
Frequently asked questions
When are Mississippi state taxes due in 2026?
Your 2025 Mississippi individual income tax return is due April 15, 2026. If that date falls on a weekend or legal holiday, the deadline moves to the next business day. An extension moves the filing deadline to October 15, 2026, but any tax owed is still due on the original date.
When are Mississippi estimated tax payments due in 2026?
Mississippi estimated payments for the 2026 tax year are due April 15, 2026, June 15, 2026, September 15, 2026, January 15, 2027. Use Form 80-106 or pay online. The final installment for 2025 was due January 15, 2026.
Does Mississippi accept the federal extension?
Yes. A federal extension is honored; no state form. The extended filing deadline is October 15, 2026, and tax is still due by April 15, 2026.
Does a Mississippi extension give me more time to pay?
No. An extension extends the time to file, not to pay. To avoid penalties and interest, pay what you expect to owe by April 15, 2026.
Dates are the statutory deadlines that fall in 2026 and move to the next business day when they land on a weekend or holiday. Each section links to the source it was checked against. Always confirm with the Mississippi tax agency or the IRS before relying on a date. This is general information, not tax advice.