Mississippi Form 80-105: Filing the Final Income Tax Return After Death

The bank account is frozen. The estate attorney has not returned your call. And somewhere in the pile of paperwork is a notice that a tax return needs to be filed for the person who died. If the decedent was a Mississippi resident, that return is Form 80-105 — the standard Mississippi Resident Individual Income Tax Return — and it needs to be filed whether or not the executor has opened a formal probate case.

Many families assume that death ends tax obligations. It does not. What it does is set a hard cutoff date for the personal return and transfers ongoing tax responsibility to the estate itself. Here is exactly what the executor or surviving spouse needs to do.

Who Is Required to File Form 80-105

A final Form 80-105 must be filed for any Mississippi resident who died during the tax year if their gross income from the beginning of the year up to the date of death met the standard filing threshold. For the 2025 tax year, the Mississippi Department of Revenue applies the same filing thresholds used for living taxpayers — generally $8,300 for a single filer and $16,600 for married filing jointly, though these figures adjust annually.

If the decedent's income fell below the threshold, no state return is required — but a federal return still may be.

If the decedent was a non-resident or part-year resident who earned income from Mississippi sources, the appropriate form is Form 80-205, not 80-105.

The Deadline: April 15

The final Form 80-105 is due by April 15 of the year following the year of death. If the person died in 2025, the final return is due April 15, 2026.

Mississippi automatically honors federal filing extensions, so if the executor requests an IRS extension, the state deadline extends accordingly. However — and this is critical — an extension to file is not an extension to pay. Any tax balance owed must be paid by April 15 using Form 80-106 (the extension payment voucher) regardless of whether additional time has been requested to file.

Late payment incurs interest at 0.5% per month plus a late payment penalty of 0.5% per month, capping at 25% of the balance. Do not delay payment while waiting to finalize the return.

How to Prepare the Final Return

Step 1: Mark the Return as Deceased

At the top of Form 80-105, immediately after the decedent's name, write the word "DECEASED" followed by the exact date of death. This notation alerts the Mississippi Department of Revenue that the return is a final filing and should not be expected in future years.

Step 2: Choose the Correct Filing Status

• Single — if the decedent was not married at the time of death
• Married Filing Jointly — if the surviving spouse elects to file a joint return for the year of death. The surviving spouse must select the specific status "Married Spouse Died" on the return.
• Married Filing Separately — if the surviving spouse prefers to file a separate return

Filing jointly is generally advantageous because it allows the surviving spouse to claim the full standard deduction of $12,000 and the full personal exemption of $4,600 for the year of death, plus an additional $1,500 per claimed dependent.

Step 3: Report Only Income Earned Before Death

This is the rule most executors misapply. The final Form 80-105 reports only income that the decedent actually earned, received, or constructively received up to the date of death. Nothing more.

Any income generated by the decedent's assets after the date of death — dividends from a brokerage account, rent from an inherited house, interest accumulating in a savings account — belongs to the estate, not the decedent. That income must be reported separately on the Mississippi Fiduciary Income Tax Return (Form 81-110). Mixing post-death estate income into the personal return is a common and costly mistake.

Step 4: Claim All Available Deductions

The truncated tax year does not reduce the deductions available. The executor can claim the full standard deduction, all applicable exemptions, and — if the decedent was over 65 or legally blind — the additional exemptions available under those circumstances. Mississippi does not prorate deductions for a partial tax year.

Step 5: Attach Required Documentation

Do not submit the return without these attachments:

• A certified copy of the official death certificate
• Federal Form 1310 (Statement of Person Claiming Refund Due a Deceased Taxpayer), if a refund is expected and the filer is not the surviving spouse or court-appointed executor. The Form 1310 identifies who is authorized to receive the refund.
• Evidence of fiduciary authority — typically the court-issued Letters Testamentary or Letters of Administration — if the executor is filing on behalf of the estate

If the surviving spouse is filing a joint return and a refund is owed, Form 1310 is generally not required for the spouse.

Claiming a Refund: Two Paths

If the final return produces a refund, the executor faces a procedural decision:

Option 1 — Standard refund claim: Attach Form 1310 and the death certificate. The Department of Revenue will issue the refund check. If the check is issued in the decedent's name, the authorized heir must present it to a financial institution along with a completed Statement of Heirship (Form 80-699) to authorize cashing.

Option 2 — Bypass formal estate administration for small refunds: If the refund is less than $500, Mississippi law allows the funds to be disbursed directly to an heir using the Form 80-699 without requiring a full probate proceeding. This is a meaningful shortcut for small estates where the primary or sole asset is the state tax refund.

What Comes Next: The Fiduciary Return

Filing Form 80-105 closes the decedent's personal tax account. But if the estate remains open for months — which is common in Mississippi, where creditor notification alone takes 90 days — the estate itself will likely generate income. Bank accounts earn interest. Investment accounts generate dividends. Rented property produces rental income.

All of that post-death income belongs to the estate and must be reported on the Mississippi Fiduciary Income Tax Return, Form 81-110. The fiduciary return is a separate filing with its own deadlines, its own penalty structure, and its own reconciliation requirements tied to the federal Form 1041.

The Mississippi Final Tax & Estate Tax Guide covers both the personal final return and the fiduciary return in full — including the specific line-by-line instructions for Form 80-105, the sequence for attaching Form 1310, and how to prevent personal liability for premature distributions before tax obligations are cleared.

Common Mistakes to Avoid

Including post-death income on the personal return. Any income earned after the date of death belongs on Form 81-110, not 80-105. Including it on the personal return misrepresents the estate's tax position.

Filing without Form 1310. If anyone other than the surviving spouse or court-appointed executor files for the refund, the Department of Revenue will reject or delay the refund without this form.

Missing the April 15 deadline and not paying on time. The extension only extends the filing deadline. Tax owed accrues penalties from April 15 regardless.

Using the wrong form. Non-residents who earned Mississippi income need Form 80-205. Filing on 80-105 for a non-resident creates processing delays and may require an amended return.

Assuming the state uses the same rules as the IRS. Mississippi does not allow a surviving spouse to file as a "Qualifying Surviving Spouse" for two years after death the way federal law does. The final joint return covers only the year of death.

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