Illinois Estate Tax Nonresident Guide
Last updated: 18 Oct 2025 • Author: Alexander Foelsche CPA (US), WP (DE), RE (CH)
Illinois Estate Tax — Nonresident Guide
For estates of decedents domiciled outside Illinois that own Illinois-situs assets. This page covers who must file, what’s taxable, how Illinois limits tax to Illinois property, deadlines & extensions, payment routing, and practical checklists.
Do you need to file as a nonresident?
What counts as Illinois-situs property?
| Asset type | Taxed by Illinois? | Notes |
|---|---|---|
| Real property located in Illinois | Yes | Homes, farmland, commercial property. Use local appraisals. |
| Tangible personal property kept in IL | Yes | Boats, vehicles, equipment, art physically in IL. |
| Intangibles (stock, bonds, cash, brokerage) | Generally no | Usually sourced to domicile; may be drawn in only if they acquire an IL business situs. |
| Entity interests (LLC/partnership) | Generally no | Treated as intangibles; avoid IL business-situs facts (management/records in IL, operations centered in IL). |
How Illinois limits the tax to the Illinois portion
- Illinois computation starts from the “state death tax credit” framework and then reduces the result for non-Illinois property; for a nonresident, only Illinois-situs assets remain in the base.
- Deductions should be supportable and tied to the reported property; keep probate orders, invoices, and proof of payment.
- Federal schedules (Form 706 or pro-forma) provide valuation scaffolding; attach relevant pages to Form 700.
Bottom line: compute the Illinois portion accurately; exclude property that is not Illinois-situs for a nonresident decedent.
Deadlines, extensions & payment
| Item | Timing | Notes |
|---|---|---|
| Form 700 due | 9 months after death | Illinois follows the federal 9-month rule. |
| Extension to file | 6 months (typical) | Attach IRS Form 4768 approval or file Form 700-EXT with the Attorney General by the original due date. Extensions do not extend time to pay. |
| Paying the tax | By 9 months | Remit to the Illinois State Treasurer (use the Treasurer’s Estate Tax Payment Form/instructions). Record any payments on Form 700. |
| Installments | With return/election | If federal §6166 applies, Illinois generally aligns proportionally for Illinois-situs business interests. |
Core forms (nonresident focus)
Illinois forms
- Form 700 — Illinois Estate & GST Tax Return (include IL-only QTIP schedules if applicable).
- Form 700-EXT — Extension to file/pay (if needed in addition to or instead of federal extension).
- Treasurer Estate Tax Payment Form — For remitting payment to the State Treasurer.
Federal attachments
- Form 706 pages/schedules (or pro-forma if no federal filing), Forms 712 (life insurance).
- Deeds, appraisals, proof of IL location; will/trusts and letters of authority.
Follow the AG instructions for the full attachment checklist.
Quick examples
Example — Chicago condo to children
Nonresident decedent owns a Chicago condo and out-of-state investments. The Illinois return includes the condo (and IL-tied deductions) only; non-Illinois accounts are excluded from the Illinois base.
Example — Boat stored in Illinois to nephew
Boat kept in Illinois passes to a nephew. The boat is Illinois-situs tangible property and is included in the Illinois computation even if most assets are outside IL.
Nonresident filing checklist
Documents
- Death certificate; letters of appointment (domicile state and any IL ancillary).
- List of Illinois-situs assets with appraisals and location evidence.
- Federal schedules (706/pro-forma), will/trusts, beneficiary designations.
Computations & timing
- Compute the Illinois portion on Form 700; exclude non-Illinois assets.
- Target the 9-month payment date; if needed, request an extension to file (not to pay).
- Plan for the State Treasurer payment and retain proof of remittance.
FAQs — Nonresident estates
Are nonresidents taxed on brokerage accounts?
Generally no. Intangibles (e.g., brokerage, stock, cash) of a nonresident are typically not Illinois-situs unless they acquire a business situs in Illinois.
Do I have to file if there’s no Illinois property?
Usually not. If the decedent had no Illinois-situs assets, an Illinois estate tax return is not generally required. Verify titles and locations carefully.
How are payments handled?
File Form 700 with the Attorney General; send payment to the Illinois State Treasurer using the Treasurer’s instructions/form.
What if a federal estate return isn’t required?
You may still need an Illinois filing. Use federal-style schedules as pro-forma support and follow the AG attachment checklist.