If you filed your federal return as Married Filing Jointly (MFJ), Illinois may allow you to file your Illinois return as Married Filing Separately (MFS) in certain situations. When this election is made, income, deductions, and dependents from the joint federal return must be allocated between spouses for Illinois purposes. Illinois specifically provides allocation rules and an Allocation Worksheet for taxpayers making this election.
When Can I Change From MFJ to MFS for Illinois?
Illinois generally requires you to use the same filing status as your federal return. However, there are exceptions. You may need or choose to file separately for Illinois if:
- You filed a joint federal return and are an injured spouse.
- One spouse is an Illinois resident and the other spouse is a nonresident or part-year resident.
- You want to protect your Illinois refund from being applied to a spouse's debt owed to a government agency.
Illinois allows certain taxpayers who filed a joint federal return to file separate Illinois returns using the Married Filing Separately status.
What Happens When I File MFS for Illinois Only?
When you switch from MFJ to MFS for Illinois purposes:
- The joint federal return is not recalculated.
- Income must be divided between spouses.
- Adjustments to income must be divided between spouses.
- Dependents must be assigned to one spouse or the other.
- Illinois tax calculations are performed separately for each spouse.
Illinois instructs taxpayers to allocate items from the federal return between spouses using the Illinois Allocation Worksheet.
How Do I Change My Filing Status for Illinois Only?
Step 1: Open the Illinois Return
Navigate to the Illinois return and locate the MFS Allocation for State Purposes Only section.
Step 2: Indicate You Want to Change Filing Status
Answer:
Do you want to change the state filing status from MFJ to MFS?
Select Yes.
Step 3: Select the Taxpayer
Choose whether the Illinois return being prepared is for:
- Taxpayer
- Spouse
Step 4: Review and Allocate Income
The program will display income items from the joint federal return that must be allocated between spouses.
Examples include:
- State and local tax refunds
- Capital gains or losses
- Other gains or losses
- Rental income
- Taxable IRA distributions
- Other income items
Review each amount and adjust as necessary so that the Illinois return reflects only the income belonging to the selected spouse.
Step 5: Review and Allocate Adjustments
The screen also includes adjustment items such as:
- Student loan interest
- Self-employed health insurance deduction
- Alimony paid
- Tuition and fees deduction
- Penalty on early withdrawal of savings
- Archer MSA deduction
- Other adjustments
Allocate these items to the appropriate spouse.
Step 6: Assign Dependents
Select which dependents should be claimed on the Illinois return for the spouse being entered.
Step 7: Complete the Return
Continue through the Illinois interview and review the completed return before filing.
Program Path
State Return > Illinois Return > Basic Information > Change Filing Status from MFJ to MFS for State Purposes Only
The screen allows you to allocate income, adjustments, and dependents between spouses for Illinois filing purposes.
Frequently Asked Questions
Do I need to amend my federal return?
No. Illinois instructs taxpayers not to recalculate the joint federal return. Instead, the federal amounts are allocated between spouses for Illinois reporting purposes.
Can one spouse file as an Illinois resident and the other as a nonresident?
Yes. Illinois specifically addresses situations where one spouse is a full-year resident and the other is a part-year resident or nonresident. In those cases, filing separately may be required or beneficial.
What is an injured spouse?
An injured spouse is a taxpayer whose spouse owes a debt to a government agency and who wants to prevent the entire Illinois refund from being applied to that debt. Illinois allows eligible taxpayers to file separate Illinois returns in these situations.
Can I switch back to a joint Illinois return later?
Illinois states that once the filing status election becomes final after the extended due date, the decision is generally irrevocable for that tax year.
How should I split income and deductions?
Income and deductions should be allocated to the spouse to whom they belong. Illinois provides an Allocation Worksheet for dividing items reported on the joint federal return.
Helpful Tips
- Have a copy of your joint federal return available before completing the allocation screen.
- Review Forms W-2, 1099, and Schedule K-1 documents to determine ownership of income.
- Verify all adjustments are assigned to the correct spouse.
- Carefully review dependent assignments before filing.
- Compare the completed Illinois return to the Illinois Allocation Worksheet if needed.
- Keep documentation supporting how income and deductions were allocated between spouses.
Additional Information
Illinois provides a dedicated Allocation Worksheet for taxpayers who file a joint federal return but choose or are required to file separate Illinois returns. The worksheet divides federal income and adjustments between spouses and serves as the basis for preparing separate Illinois returns.