In general, you should use the same filing status as on your federal return. However,
- if you file a joint federal return and you are an injured spouse (e.g., your spouse owes a liability, for which you are not responsible, to a government agency), you should file separate Illinois returns using the “married filing separately” filing status. Do not recompute any items on your federal return. Instead, you must divide the income shown on your joint federal return between your separate Illinois returns following the federal Form 8379, Injured Spouse Allocation, Part III.
You may choose to file separately as an injured spouse only until the extended due date of the return, and once you choose a filing status the decision is irrevocable for the tax year.
- if you file a joint federal return and one spouse is a full-year Illinois resident while the other is a part-year resident or a nonresident (e.g., military personnel), you may choose to file “married filing separately.” Do not recompute any items on your federal return. Instead, you must divide the income shown on your joint federal return between your separate Illinois returns following the federal Form 8379, Part III.
If you choose to file a joint Illinois return, you must treat both your spouse and yourself as residents. This election is irrevocable for the tax year. You may be allowed a credit for income tax paid to another state on Schedule CR. For more information, see the Schedule CR instructions.
- if you are in a same-sex civil union as of December 31, 2011, you must file a paper Form IL-1040 with your civil union partner using either the “married filing jointly” or “married filing separately” filing status.
Since a same-sex civil union couple may not file a federal return using a married filing status,
- if you and your partner choose to file a joint Illinois return, you must recompute your adjusted gross income as if you had filed a federal married filing jointly return.
- if you and your partner choose to file separate Illinois returns, you must recompute your adjusted gross income as if you had both filed federal married filing separately returns, for Illinois purposes only.
Complete your federal “as-if-married” return, including all schedules and attachments, applying all the federal rules for the married filing status you choose. Enter the federal “as-if-married” return information where Illinois requires federal information. Do not file your federal “as-if-married” return with the IRS.
Note: If you choose to file a joint Illinois return, you and your partner will both be liable for the joint tax liability, and each partner’s share of any joint refund may be applied against unpaid liabilities of the other partner.
Note: If you are an Illinois resident, and your partner is not, and you choose to file a joint Illinois return, you must treat both yourself and your partner as residents
