How to Fill Out Mississippi Form 80-160: Credit for Tax Paid to Another State

Mississippi Form 80-160 is the worksheet a Mississippi resident uses to calculate the credit for income tax paid to another state, so the same dollars are not taxed twice. You complete it alongside your Mississippi Resident Individual Income Tax Return (Form 80-105), and the final credit lands on line 18 of that return.¹ One form handles up to three other states at once.

Who Can Use the Form

The credit is for legal residents of Mississippi only. If you lived in Mississippi and earned income in another state, a U.S. territory, or the District of Columbia and paid income tax there, you qualify.² Nonresidents and part-year residents file on different forms and do not use 80-160.

The credit covers income taxes only. Sales tax, property tax, and other state-level taxes paid elsewhere do not count. Typical users are cross-border commuters into Tennessee, Alabama, Louisiana, or Arkansas, residents with rental property in another state, and owners of businesses operating in more than one state.

How Much Credit You Can Actually Claim

Before you start filling in boxes, know what the form is driving toward. Mississippi caps the credit at the smallest of three figures:²

Your total Mississippi income tax for the year.
The income tax you actually paid to the other state.
What Mississippi’s rates would produce on the net taxable income you reported to the other state.

If the other state’s rate is higher than Mississippi’s, your credit is capped at the Mississippi tax on that income. If it’s lower, you get full credit for what you paid. There is no carryforward for any unused portion, and the credit cannot generate a refund on its own.

Filling Out the Form Line by Line

Download the current year’s Form 80-160 from the Department of Revenue’s form search page.³ Have your finished Form 80-105 in front of you, plus the completed return for each other state. You cannot calculate the credit from a W-2 alone; you need the other state’s actual return to know what tax was finally owed there.⁴

The form uses six columns. Columns 1 and 2 cover the taxpayer and spouse on a joint return. Columns 3, 4, and 5 are for separate other states; write the state name above each column you use. Column 6 totals the out-of-state figures. If you only earned income in one other state, you use column 3 and leave 4 and 5 blank.

Lines 1 Through 5: Income and the State Ratio

On line 1, enter total income earned everywhere in the Mississippi columns, and the income earned in each other state in that state’s column. Lines 2 and 3 are for the deductions and exemptions from your Mississippi return and from each other state’s return. Line 4 is line 1 minus lines 2 and 3, giving taxable income for each column. Add the other-state columns to get the total in column 6.⁴

Line 5 computes a ratio for each other state: that state’s taxable income divided by the total out-of-state taxable income in column 6. With only one other state, the ratio is 1.0.

Lines 6 Through 10: Applying Mississippi’s Rates

Lines 6 through 9 take the total out-of-state taxable income, break it into Mississippi’s brackets, and apply Mississippi’s rates. The form then multiplies each bracket’s tax by the line 5 ratio to split the computed Mississippi tax across the other-state columns. Line 10 totals the result for each column. For 2026, Mississippi taxes income above $10,000 at a flat 4 percent, with the first $10,000 exempt. Use the form version matching your tax year, because rates have been changing.

Lines 11 Through 14: The Smaller-Of Comparisons

On line 11, enter the actual income tax owed to each other state, taken from that state’s return. Line 12 compares line 10 to line 11 for each state column and keeps the smaller number, which enforces the first two statutory caps.⁴

Line 13 is your Mississippi tax from Form 80-105. Line 14 takes the lesser of the column 6 total on line 12 or line 13, applying the final cap. That line 14 number goes on Form 80-105, page 1, line 18.¹

What You Must Attach

Form 80-160 by itself is not enough. The Department of Revenue requires:

A copy of each other state’s filed return. You must have actually filed, not just had tax withheld.
Proof of tax paid. A W-2 showing other-state withholding is explicitly not accepted, because withholding is only an estimate of what you might owe.⁴
A certificate of out-of-state income showing gross income, net income, net taxable income from sources outside Mississippi, and the tax paid on that income.²

The W-2 problem is the single most common reason a credit gets rejected. The final tax owed to the other state can be higher or lower than what was withheld, and Mississippi wants the final figure from a filed return.

How and When to File It

Form 80-160 is never filed on its own. Attach it, along with copies of each other-state return, to your Form 80-105. If you e-file through commercial software, those documents are bundled into the electronic submission. If you file on paper, physically attach them to the Mississippi return before mailing.⁵

Mississippi follows the federal calendar. For tax year 2025, the deadline is April 15, 2026, and an extension pushes the filing date to October 15, 2026 without extending the payment deadline.⁶ If the other state’s return is not finished by April 15, you can still file a Mississippi extension, but you should estimate and pay your Mississippi liability as if no credit applied, then claim the actual credit when the complete return goes in.

Mistakes That Get the Credit Denied

Submitting a W-2 instead of the other state’s return. Withholding is not proof of tax paid.
Entering a credit amount on line 18 of Form 80-105 without attaching Form 80-160 and the other-state return copies.
Using a prior year’s form after rate changes, which produces an incorrect bracket calculation.
Claiming a credit for sales tax, property tax, or local assessments paid in another state. Only state income taxes qualify.
Expecting the credit to generate a refund. It cannot exceed your Mississippi tax, and nothing carries forward.

1
Mississippi Department of Revenue. 2025 Mississippi Resident Individual Income Tax Return Instructions
2
FindLaw. Mississippi Code Title 27 Taxation and Finance 27-7-77
3
Mississippi Department of Revenue. Form Search
4
Mississippi Department of Revenue. Mississippi Tax Credit For Income Tax Paid To One Or More Other States
5
Mississippi Department of Revenue. Contact Information
6
Mississippi Department of Revenue. Individual Income Tax Frequently Asked Questions