Illinois lemon law: how to file and the 30-business-day test (2026)
Illinois's lemon law is the New Vehicle Buyer Protection Act (815 ILCS 380/). It covers new vehicles bought, or leased 1+ years, primarily for personal, family, or household purposes. The tests, within 1 year/12,000 miles and after the § 3(h) notice, are 4+ repairs of one nonconformity or 30+ business days out of service. The manufacturer's procedure, then circuit court.
The complete, plain-English walkthrough — built from the Illinois Attorney General's auto-sales publications and the New Vehicle Buyer Protection Act (815 ILCS 380/), not law-firm marketing. Last reviewed: October 2026.
What is the Illinois lemon law?
The Illinois lemon law is the New Vehicle Buyer Protection Act (815 ILCS 380/). It covers new vehicles bought — or leased for at least one year — primarily for personal, family, or household purposes. If a vehicle meets one of the Act's two tests below, a reasonable number of repair attempts is presumed and the manufacturer may have to repurchase or replace it. Suit under the Act must be commenced within 18 months of original delivery.
- Four-times test: the same nonconformity was repaired 4 or more times and still exists.
- 30-business-day test: the vehicle was out of service for repair a cumulative 30 or more business days.
- Direct notice (§3(h)): the tests count only repairs within the statutory warranty period — 1 year or 12,000 miles from delivery, whichever comes first — and the manufacturer must have received prior direct written notification with an opportunity to correct.
Illinois's law covers new vehicles; used cars are not covered by it. If you bought used, see our used-car lemon law guide for the rules that can apply to used vehicles instead.
⚡ Start here — three free tools
Illinois lemon law quiz (3 minutes): compare your facts to the two tests below.
Deadline calculator: your estimated days-left count.
Buyback calculator: the usage-offset math for Illinois.
What vehicles are covered
Illinois' New Vehicle Buyer Protection Act (815 ILCS 380/) covers new vehicles bought — or leased for at least one year — primarily for personal, family, or household purposes: passenger cars, trucks and vans under 8,000 pounds, and recreational vehicles (except camping and travel trailers).
Not covered (per the Illinois AG): used cars, altered or modified vehicles, motorcycles, and boats.
The two tests (no safety shortcut)
A "reasonable number of attempts" is presumed if, within the statutory warranty period — 1 year or 12,000 miles from delivery, whichever first — any one of these happened, and the manufacturer received prior direct written notification with an opportunity to correct (§3(h)):
1. Four-times test
The same nonconformity persists after 4 or more repair attempts. Different defects don't combine — it must be the same nonconformity. Keep the dates, repair-order numbers and reported problems together in the free repair log.
2. 30-business-day test
The vehicle was out of service by reason of repair a cumulative 30+ business days. Days need not be consecutive.
No safety shortcut: Illinois has no reduced-attempt test for safety defects — the same 4-times / 30-business-day thresholds apply.
§3(h): the direct-notice requirement
This is the step people miss. The presumption requires prior direct written notification to the manufacturer — not just telling the dealer — plus an opportunity to correct the nonconformity.
The statute does not require certified mail — but a trackable mailing (certified mail, return receipt requested) is the practical way to prove you sent it. Send it to the manufacturer's address in your warranty booklet; sending it only to the dealer is a risk. The LemonLawPath $29 packet includes a draft §3(h) notice letter.
The 18-month suit deadline
Suit must be commenced within 18 months of original delivery (815 ILCS 380/6). The limitations period is extended by the days the matter was pending in the informal dispute procedure — so filing with the manufacturer's program early also protects your clock.
This is the single most important date in your case. Illinois lemon law deadline calculator →
Deadlines: compute the 18-month suit date and track program time
The Illinois lemon law statute of limitations (§6 suit clock) runs 18 months from original delivery. The statutory warranty period used for the presumption is different: one year or 12,000 miles from delivery, whichever first. Under §4(b), the civil-action period is extended by the days the subject matter was pending in the informal dispute procedure. These clocks should be recorded separately, with evidence of any program dates.
Compute it from your records
- Find original delivery in the contract and delivery records. Add 18 calendar months for the unadjusted suit-date estimate. The calculator uses this baseline; it does not collect the dates necessary to apply a program-pendency extension.
- Identify the separate one-year / 12,000-mile statutory warranty window. Compare delivery plus one year with the relevant mileage milestone. Check when the repair attempts and business days out of service occurred rather than assuming the longer suit period extends the presumption window.
- If you used the informal dispute procedure, retain confirmation of when the matter began and ended there. Ask an attorney to confirm the number of pending days and the adjusted court date under §4(b). Do not treat ordinary dealer visits or manufacturer correspondence as program-pendency days.
- Check the direct written manufacturer notice and opportunity-to-correct requirement separately. The AG warns that a claim cannot be started through the dealer and that waiting longer than 12 months from purchase has caused consumers to lose remedies. The 18-month suit calculation is not permission to delay the earlier steps.
If the date appears missed
If the estimate appears passed, talk to a licensed Illinois attorney promptly before purchasing a packet. Missing an applicable deadline may put the statutory remedy at risk. The calculator cannot decide whether an extension applies or whether another law provides an option. Bring the warranty, repair orders, notice proof, and program records so the dates can be evaluated together, rather than assuming one date answers every question.
Keep a copy of the inputs and calculation, and revisit them if you obtain better records. An estimate is useful for organizing questions; the state agency or a licensed attorney must confirm uncertain timing. Do not treat missing information as extra time.
Primary sources: 815 ILCS 380, §§3, 4 and 6 · Illinois AG auto guidance
How to file: program, then circuit court
- Step 1 — the manufacturer's informal dispute procedure: find it in your owner's manual or warranty booklet. If a qualifying program exists and you were told about it in writing, you must use it before the Act's remedies apply. The AG warns that claims can't be started through the dealer, and that many consumers lost their remedy by waiting longer than 12 months from purchase. The program is free to you.
- Step 2 — circuit court: if the program doesn't resolve it, claims are brought in circuit court. The Act sets no filing fee of its own, but circuit-court clerk filing fees apply and vary by county.
Important caveat: the Illinois lemon law has no attorney's-fee provision — unlike some states, it does not shift your legal fees to the manufacturer. Whether any other law could apply to your facts is a question for an attorney.
What happens after you file
- Program decision — the manufacturer's informal dispute procedure decides. If you're dissatisfied, you can still bring a civil action (the program's decision can be used as evidence).
- Circuit court — if unresolved, a civil action in circuit court with normal court procedure.
Remedies: repurchase, replacement
- Repurchase: the full purchase price or lease cost, including collateral charges (collateral charges don't include taxes the purchaser paid on the initial purchase; the Act's definition of lease cost does include taxes), less a reasonable allowance for your use — the wear and tear from use before you first reported the nonconformity to the seller, plus use during later periods when the vehicle wasn't out of service for repair (§3(c)).
- Replacement: a new vehicle of like model line, if available — otherwise a comparable motor vehicle.
More on repurchase math: the Illinois lemon law buyback guide covers what a buyback includes and how the reasonable use allowance is counted.
When to talk to a lawyer instead
LemonLawPath is for straightforward, DIY-able cases. Talk to a licensed lemon law attorney if any of these apply:
- Your defect is a serious safety hazard;
- The manufacturer denied your claim or disputes the defect;
- Your 18-month deadline has passed or is under 30 days away;
- Anything about your case feels ambiguous.
Because Illinois' lemon law has no fee-shifting, ask any attorney how they charge before you hire them.
Common questions
What are the Illinois lemon law tests?
Within the statutory warranty period — 1 year or 12,000 miles from delivery, whichever comes first — a reasonable number of attempts is presumed if the same nonconformity was repaired 4 or more times and still exists, or the vehicle was out of service 30 or more business days. The manufacturer must also have received prior direct written notification and an opportunity to correct (§3(h)).
What is the Illinois lemon law deadline?
Suit must be commenced within 18 months of original delivery (815 ILCS 380/6). The period is extended by the days the matter was pending in the manufacturer's informal dispute procedure.
Does Illinois have state lemon law arbitration?
No. If the manufacturer has a qualifying informal dispute program and you were told about it in writing, you must use it first; after that, claims go to Illinois circuit court.
Does the Illinois lemon law make the manufacturer pay attorney's fees?
The Illinois lemon law has no attorney's-fee provision — unlike some states, it doesn't shift your legal fees to the manufacturer.
Can I start an Illinois lemon law claim through the dealer?
The Illinois Attorney General says lemon law claims can't be started through the dealer, and warns that many consumers lost their remedy by waiting longer than 12 months from purchase.
Is there a 15-day lemon law in Illinois?
No. Illinois has no 15-day lemon law test. The Act's tests are 4 or more repair attempts for the same nonconformity, or a cumulative 30 or more business days out of service for repair — business days, not calendar days. The repairs must fall within the statutory warranty period of 1 year or 12,000 miles from delivery, and the manufacturer must have received prior direct written notification with an opportunity to correct (§3(h)).
Does Illinois's lemon law cover used cars?
No. Per the Illinois Attorney General, used cars are not covered by the New Vehicle Buyer Protection Act, which covers new vehicles bought, or leased for at least one year, primarily for personal, family, or household purposes. See our used-car lemon law guide for how used vehicles are treated.
Ready? Build your packet.
Personalized claim narrative, repair-history organizer, evidence checklist, §3(h) notice letter, and filing instructions — $29 one-time. The Illinois lemon law sets no filing fee of its own; circuit-court filing fees vary by county.
Preview the Illinois DIY packet → Compare your Illinois repair history
See a finished example first: sample Illinois packet (PDF) · sample Illinois packet (Word) — all five documents with fictional data, produced by the same builder.
Sources: Justia — 815 ILCS 380/ (statute reprint) · IL AG — Auto Sales and Repairs