Does Illinois have inheritance or gift tax?

Illinois imposes an estate tax, not an inheritance tax. There is no separate Illinois gift tax; however, certain lifetime taxable gifts are included in the Illinois estate computation.

What’s the 2025 Illinois estate tax threshold and rate structure?

The exclusion is $4,000,000 (not indexed and not portable). Illinois uses the pre-2005 federal state death tax credit schedule (0.8% up to 16%) with an interrelated computation.

How are nonresidents taxed on Illinois property?

Nonresidents are taxed on Illinois-situs real and tangible personal property. The estate computes the full Illinois tax and then prorates by Illinois-situs assets divided by total assets.

When is the Illinois estate tax return due and how do I file?

The Illinois return (Form 700) is generally due within 9 months of death. Extensions are available (Form 700-EXT or federal Form 4768), but interest may accrue until payment.

Is there an Illinois-only QTIP election?

Yes. Illinois allows a QTIP election for state purposes even if a different federal QTIP is chosen. The election is made on Form 700.

Illinois Estate Tax Guide

Q: Does Illinois have an estate or an inheritance tax?

Illinois has a state estate tax paid by the estate, based on federal concepts with Illinois-specific filing rules and a separate state exclusion.

Q: When is Illinois Form 700 due, and can I extend?

Nine months after death. You can extend time to file by about six months (federal Form 4768 or Illinois Form 700-EXT). Payment remains due at nine months.

Q: How are nonresidents taxed?

Only on Illinois-situs real and tangible property. Most nonresident intangibles are excluded unless an Illinois business situs exists.

Illinois Estate Tax Guide (2025) — Exclusion, IL-Only QTIP, Nonresident Situs, Form 700 & Deadlines

Last updated: 10 Nov 2025 • Author: Alexander Foelsche CPA (US), WP (DE), RE (CH)

Illinois Estate Tax & Probate — Complete Guide

What executors and families need to know about Illinois probate and estate tax: $4,000,000 exclusion, Illinois-only QTIP election, who files, what’s taxable, nonresident situs rules, Form 700 & 700-EXT, deadlines & payment to the State Treasurer, examples, planning—and a calculator.

Get help: Illinois Estate Tax Service (fixed-fee)

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Quick orientation: Illinois imposes a state estate tax under 35 ILCS 405. The estate return is Form 700 and is generally due 9 months after death. You can extend time to file via IRS Form 4768 (recognized) or Illinois Form 700-EXT; payment remains due at 9 months and is remitted to the Illinois State Treasurer.

Illinois Inheritance & Probate Basics

Courts & intestacy

Probate is handled in the Illinois circuit courts. If there is no will, distribution follows Illinois intestacy statutes. Ancillary probate is common where nonresidents own Illinois real property.

How Illinois probate works

Open estate → appoint personal representative → notices → inventory & appraisals → pay debts/expenses/taxes → accountings → distribution & close. Streamlined options may apply for certain small estates.

Illinois Estate Tax — At a Glance

Who is taxed?

Illinois levies a state estate tax on estates of Illinois residents and on nonresidents to the extent of Illinois-situs real/tangible property (see 35 ILCS 405).

Exclusion & computation

Illinois maintains its own exclusion (commonly referenced as $4,000,000 in recent years) with a computation tied to the pre-2005 federal state death tax credit framework.

IL-only QTIP

Illinois allows a separate state QTIP election on a timely filed Form 700, even if no federal QTIP is made. Inclusion occurs at the survivor’s death.

Situs rules

Real property located in Illinois and tangible personal property normally kept in Illinois are included; most nonresident intangibles are excluded unless a business situs exists in Illinois.

Due date

Return and payment due 9 months after death; you can extend time to file (IRS 4768 or IL 700-EXT) but not time to pay.

Who must file?

The personal representative files Form 700 when Illinois estate tax is due or to make elections (e.g., IL-only QTIP). Nonresidents file when Illinois-situs assets are involved.

Need a quick estimate? Try the Illinois Estate Tax Calculator.

Official Pages, Forms & Where to File/Pay

Illinois Attorney General — Estate Taxes (Form 700, 700-EXT, fact sheets, calculator).
Statute: Illinois Estate & GST Tax Act (35 ILCS 405).
Payment: Illinois State Treasurer — Estate Tax payments (payment form & instructions).
Federal: IRS Form 706 & instructions — IRS page.

Illinois Situs vs. Non-Situs Property (Nonresidents)

Asset type	Illinois treatment	Notes
Real property in Illinois	Included	Use local appraisals; common for ancillary probate.
Tangible personal property kept in IL	Included	Boats, vehicles, equipment, artwork physically in IL.
Intangibles (stock, bank/brokerage)	Generally excluded	Excluded for nonresidents unless a business situs exists in Illinois.
Entity interests (LLC/partnership)	Generally excluded	Treated as intangibles; avoid IL business-situs facts.

Nonresidents with Illinois real/tangible property may owe Illinois estate tax even when most assets are outside Illinois; exposure is limited to IL-situs assets through Illinois’ computation framework.

Filing Mechanics & Deadlines

When to file: Form 700 due within 9 months from date of death (same as federal).
Extension to file: typically about 6 months (attach IRS 4768 approval or file Illinois Form 700-EXT). Payments remain due at 9 months.
Where to file: File the return with the Illinois Attorney General.
Where to pay: Remit tax to the Illinois State Treasurer using the Treasurer’s estate tax payment form/instructions.
Installments: If federal IRC § 6166 applies, Illinois generally aligns proportionally for Illinois-situs business interests.

Planning Ideas to Reduce Illinois Estate Tax

IL-only QTIP. Make a state QTIP election to defer tax at the first death even if no federal QTIP is desired.
Credit shelter & charitable planning. Coordinate with the interrelated Illinois computation; attach robust support.
Nonresident situs. Limit Illinois-situs assets for nonresidents; avoid business situs for intangibles.
Valuation & deductions. Use strong local appraisals; keep court orders/invoices to support deductions.
Liquidity & § 6166. Stage cash for the 9-month payment; align any federal § 6166 election with Illinois schedules.

For step-by-step implementation, see the dedicated Illinois Estate Tax Planning page, review Case Notes, or run a quick estimate with the Calculator.

FAQs

Does Illinois have an estate or an inheritance tax?

Illinois has a state estate tax (paid by the estate). It follows federal concepts with Illinois-specific filing rules and a separate state exclusion.

What is the Illinois estate tax exclusion?

Illinois maintains its own exclusion (commonly referenced as $4,000,000 in recent years) and uses an Illinois-specific computation tied to the former federal credit.

When is Illinois Form 700 due, and can I extend?

Nine months after the date of death. You can extend time to file by about six months (federal Form 4768 approval or Illinois Form 700-EXT); time to pay is not extended.

How are nonresidents taxed?

Only on Illinois-situs real and tangible property. Most nonresident intangibles are excluded unless an Illinois business situs exists.

Can I make a QTIP election for Illinois only?

Yes. A separate state QTIP election may be made on a timely filed Form 700, even if no federal QTIP is made.

Need help filing or planning?

We assist with Illinois probate coordination, resident and nonresident filings, IL-only QTIP and charitable elections, valuation documentation, and § 6166 liquidity planning.

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