Who must serve a Section 24 notice in Illinois?

Any party that does not have a direct contract with the property owner — including subcontractors, sub-subcontractors, and material suppliers — must serve a Section 24 notice to preserve their mechanic lien rights. General contractors who contract directly with the owner are exempt.

How is the 90-day Section 24 deadline calculated?

The 90-day period starts from the claimant's last date of furnishing labor or materials to the project. Punch-list work and warranty returns generally do not extend the deadline. The notice is deemed served on the date of mailing.

How do I serve a Section 24 notice?

The notice must be sent by registered or certified mail, return receipt requested, with delivery limited to the addressee only, or served personally on the property owner, their agent, architect, or the superintendent in charge of the building, and to the lending agency if known.

What must the Section 24 notice contain?

The notice must identify the claimant, state the amount due or to become due, describe the nature of the work or materials furnished, and identify the property. The statute provides a form notice that satisfies these requirements.

What happens if I miss the 90-day Section 24 deadline?

Missing the Section 24 deadline generally extinguishes your mechanic lien rights, unless an exception applies — for example, if the claimant was listed on the general contractor's sworn statement under Section 5 of the Act.

Is there an exception to the Section 24 notice requirement?

Yes. Section 24(a) provides that the notice is not required when the sworn statement of the contractor or subcontractor under Section 5 serves to give the owner notice of the amount due and to whom it is due.

Does the Section 24 notice guarantee my lien amount?

No. A subcontractor's lien is limited to the amount the owner owes the general contractor at the time the Section 24 notice is received. If the owner has already paid the GC in full, the lien may be extinguished entirely.

Do I also need to serve a 60-day notice on residential projects?

Yes. On owner-occupied single-family residences, subcontractors must serve a separate 60-day notice under 770 ILCS 60/5(b) within 60 days of the first day they furnished lienable material or services — in addition to the 90-day Section 24 notice. These are independent requirements.

Can I serve the Section 24 notice early?

Yes. You can serve the Section 24 notice at any time after you begin work — including before the 90-day window opens. Early service is often strategically advantageous because it locks in the amount the owner owes the GC at the time of receipt.

770 ILCS 60/24 Notice Requirements

Illinois Notice to Owner

Q: What is the Section 24 notice under Illinois mechanic lien law?

The Section 24 notice is a written notice that subcontractors and suppliers must serve on the property owner within 90 days of their last date of furnishing labor or materials. It informs the owner that the claimant has not been paid and preserves the claimant's mechanic lien rights under 770 ILCS 60/24.

Illinois law requires subcontractors and suppliers to notify the property owner before filing a mechanic lien. There are two separate notice requirements — and missing either one can cost you your lien rights.

Last updated: March 2026

Under 770 ILCS 60/24, if you are a subcontractor, sub-subcontractor, or material supplier on an Illinois construction project and you do not have a direct contract with the property owner, Illinois law requires you to send the owner a formal written notice before you can file a mechanic lien. Think of it as your way of putting the owner on notice: "I worked on your property, and I have not been paid." If you need an experienced mechanic lien attorney, Emalfarb Law can help.

90-Day Notice Requirements

Under 770 ILCS 60/24(a), subcontractors, sub-subcontractors, and material suppliers must serve written notice on the property owner within 90 days of their last date of furnishing labor or materials. This notice preserves your mechanic lien rights and is the most critical compliance step for parties below the general contractor in the construction chain.

Who Must Serve the 90-Day Notice

Section 24 applies to every party that does not have a direct contract with the property owner. This includes subcontractors, sub-subcontractors (and lower tiers), material suppliers, and equipment lessors whose materials or equipment are incorporated into the improvement. General contractors who contract directly with the owner are exempt because the owner already knows the identity of the GC and the amounts owed.

The purpose of the notice is to inform the property owner that a party further down the construction chain has furnished labor or materials and has not been paid. Without this notice, the owner has no way to know that payment from the general contractor has not reached the subcontractor or supplier — and Illinois law will not impose lien liability on the owner without that knowledge.

For a detailed breakdown of how subcontractor lien rights differ from general contractor rights, see our subcontractor lien rights guide.

The 90-Day Deadline

90 Calendar Days from Last Furnishing

The 90-day period begins on the claimant's last date of furnishing labor or materials to the project. This is not the last invoice date, not the last payment date, and not the date the project was substantially complete — it is the last day the claimant actually performed work or delivered materials to the job site.

The notice is deemed served on the date of mailing, not the date of receipt. This means that if a subcontractor mails the Section 24 notice on the 90th day, it is timely — even if the owner does not receive it for several more days.

Critical: Punch-list work, warranty callbacks, and return visits solely to inspect completed work generally do not extend the 90-day window. Courts look at the last date of contract work or contracted extra work, not de minimis touch-ups. Review our full deadline reference for more detail.

Parties Who Must Receive the Notice

Section 24(a) mandates that the notice be served on the following parties:

The owner of record of the property being improved, or the owner of record's agent or architect, or the superintendent having charge of the building or improvement

The lending agency (mortgage lender), if known to the claimant

Lender notice: If the subcontractor knows the identity of the lending agency and fails to include the lender in the Section 24 notice, the mechanic lien is unenforceable against that lender — even if the notice was otherwise properly served on the owner.

Delivery Methods

The statute requires the Section 24 notice to be delivered by one of two methods:

Registered or Certified Mail

The notice must be sent by registered or certified mail, return receipt requested, with delivery limited to the addressee only. The notice is deemed served on the date it is mailed, regardless of when (or whether) the recipient actually receives it. Retain the certified mail receipt and the return receipt card as proof of service.

Personal Service

The notice may be personally served on the owner, their agent, architect, or the superintendent in charge of the building. Personal service requires hand-delivery to the named individual, not merely leaving the notice at a business address or residence. Have the server prepare a written affidavit of service documenting the date, time, and person served.

Required Content of the Notice

Section 24(a) provides a statutory form notice. While the form is not mandatory, it establishes the minimum content requirements. The notice must include:

The name and address of the claimant (subcontractor or supplier)
The name of the party with whom the claimant contracted (usually the general contractor)
A description of the labor performed or materials furnished
The amount due or to become due under the contract
A description of the property sufficient to identify it (legal description or street address)
A statement that the claimant has furnished, or is furnishing, labor, services, or materials for an improvement to the property

The statutory form also includes a warning to the owner that if they make further payments to the contractor without reserving enough to cover the claimant's notice amount, they may be personally liable for the difference. While using the exact statutory form is not required, including all of these elements eliminates the risk of a challenge to the sufficiency of the notice.

Consequences of Missing the 90-Day Deadline

Missing the 90-day Section 24 deadline is one of the most common — and most devastating — mistakes in Illinois mechanic lien practice. If the notice is not served within the statutory window, the claimant's lien rights are generally extinguished. The subcontractor or supplier may still pursue a breach-of-contract claim against the general contractor, but they lose the powerful security interest in the real property that a mechanic lien provides.

Even if a late notice is served, the owner is entitled to raise the late service as a complete defense. Courts do not apply equitable tolling to the Section 24 deadline — there is no extension for ongoing negotiations, promises of payment, or the claimant's unawareness of the statutory requirement. The 90-day window is strictly enforced.

If you believe you may have missed or are approaching a Section 24 deadline, contact an Illinois mechanic lien attorney immediately. Even if lien rights are lost, other remedies — such as a construction demand letter or breach-of-contract claim — may still be available.

Exception: The Sworn Statement Under Section 5

Section 24(a) carves out a narrow but important exception: the Section 24 notice is not required "when the sworn statement of the contractor or subcontractor [as set forth in 770 ILCS 60/5] shall serve to give the owner notice of the amount due and to whom due." In practice, this means that if the general contractor's sworn statement (sometimes called a "contractor's affidavit") identifies the subcontractor or supplier by name and lists the amount owed, the owner already has constructive notice of the claim and the Section 24 notice may not be required.

However, relying on this exception is risky. Whether a particular sworn statement satisfies the statutory standard is fact-specific, and the burden of proving the exception falls on the lien claimant. The safer practice is always to serve the Section 24 notice — even if you believe you may be covered by the sworn statement exception.

Best practice: Always serve the Section 24 notice within 90 days, even if you believe you are listed on the GC's sworn statement. The cost of serving the notice is negligible compared to the risk of losing your lien rights entirely.

Strategic Timing: When to Serve the Notice

While the statute establishes a 90-day deadline, it does not prevent early service. Serving the Section 24 notice early — even at the start of the project — can be strategically advantageous. Early service locks in the amount the owner owes the general contractor at the time the notice is received, which directly determines the maximum lien amount available to the subcontractor.

If a subcontractor waits until late in the 90-day window, the owner may have already made substantial payments to the GC, reducing or eliminating the available lien amount. By serving the notice promptly — or even before the first payment is due — the subcontractor ensures the owner cannot reduce the available funds by paying the GC in the interim.

Early service also avoids the risk of miscalculating the last furnishing date and inadvertently missing the 90-day deadline. For a detailed guide on how Section 24 interacts with other lien deadlines, see our Illinois mechanic lien deadlines page or use the deadline calculator to estimate your dates.

60-Day Notice Requirements

In addition to serving the 90-day notice under 770 ILCS 60/24(a), subcontractors performing work on an owner-occupied, single-family residence must serve a separate 60-day notice under 770 ILCS 60/5(b) and 60/21(c).

60 Calendar Days from First Furnishing

The subcontractor is required to notify the owner — either personally or via certified mail — within 60 days from the first day it furnished lienable material or services of its agreement to do so. 770 ILCS 60/5(b)(ii).

Unlike the 90-day notice, which is measured from the last date of furnishing, the 60-day notice is measured from the first date of furnishing. This means the clock starts running on the very first day the subcontractor shows up on the job site or delivers materials to the project.

When Does the 60-Day Notice Apply?

The 60-day notice requirement applies only when the construction project involves an owner-occupied, single-family residence. This means:

The property must be a single-family home (not a multi-unit building, commercial property, or vacant land)
The owner must actually occupy the residence during the project
The requirement applies to subcontractors — general contractors with a direct contract with the owner are not required to serve this notice

Two Independent Requirements

The 60-day notice and the 90-day notice are completely independent requirements. Serving one does not satisfy the other. A subcontractor who serves the 90-day Section 24 notice but misses the 60-day residential notice may lose lien rights entirely — and vice versa. On owner-occupied residential projects, both notices must be served within their respective deadlines to preserve mechanic lien rights.

Side-by-Side Comparison

	90-Day Notice	60-Day Notice
Statute	770 ILCS 60/24(a)	770 ILCS 60/5(b), 60/21(c)
Deadline	90 days from last furnishing	60 days from first furnishing
Applies to	All projects (private)	Owner-occupied single-family residences only
Who must serve	Subs & lower tiers	Subs & lower tiers
Delivery	Certified mail or personal service	Certified mail or personal service

For more details on how these notice requirements interact with lien recording and enforcement deadlines, see our subcontractor lien rights guide.

Frequently Asked Questions About the Illinois Notice to Owner

Related Illinois Mechanic Lien Resources

Illinois Mechanic Lien Law

Complete guide to Illinois mechanic lien remedies

Subcontractor Lien Rights

Lien rights for subs and sub-subs under 770 ILCS 60

Material Supplier Lien Rights

Supplier-specific notice and filing requirements

Full Deadline Reference

Every lien deadline organized by claimant role

How to File a Mechanic Lien

Step-by-step filing and recording guide

Illinois Construction Law

Overview of all construction payment remedies