Late Fees on Invoices in Illinois
What Illinois contractors and small businesses need to know about charging late fees, interest rates, prompt payment laws, and mechanics lien deadlines.
Max Interest Rate
2% per month on construction (up to 24% per annum); 5% default
Small Claims Limit
$10,000
Small Claims Court (Circuit Court)
Mechanics Lien Deadline
4 months from completion for GCs; 90 days for subs
Illinois Prompt Payment Act
Illinois Prompt Payment Act, 50 ILCS 505/1 et seq.
Illinois requires government entities to pay within 60 days. Private construction payments follow contract terms with mechanics lien enforcement.
Late fee rules for Illinois invoices
Illinois allows contractual late fees but courts may void penalties. The Mechanics Lien Act provides strong interest provisions for construction work.
Illinois allows up to 2% per month on construction contracts under the Mechanics Lien Act. The default judgment rate is 5% per annum.
Important disclaimer
This page provides general information about Illinois late fee rules. It is not legal advice. Laws change, and your specific situation may have unique factors. For disputes involving significant amounts, consult a licensed attorney in Illinois.
Demand letters and mechanics liens in Illinois
Subcontractors must serve a Notice to Owner within 60 days. A demand letter is standard practice for all parties.
Mechanics lien deadline: 4 months from completion for GCs; 90 days for subs. A Notice to Owner is required for subcontractors.
Sample late fee clause for Illinois invoices
“Payment is due within the terms specified above. A late fee of 1.5% per month (2% per month on construction (up to 24% per annum); 5% default maximum per Illinois law) will be applied to all balances remaining unpaid after the due date. Pursuant to the Illinois Mechanics Lien Act (770 ILCS 60/0.01 et seq.), the undersigned reserves all rights to pursue collection including but not limited to mechanics lien filing, small claims action (up to $10,000 in Small Claims Court (Circuit Court)), and referral to collections.”
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Start Free TrialFrequently asked questions — Illinois
What is the maximum late fee I can charge on an invoice in Illinois?▾
In Illinois, Illinois allows up to 2% per month on construction contracts under the Mechanics Lien Act. The default judgment rate is 5% per annum. Always disclose late fee terms in your contract or invoice before work begins.
Does Illinois have a prompt payment act?▾
Yes. Illinois requires government entities to pay within 60 days. Private construction payments follow contract terms with mechanics lien enforcement.
What is the small claims court limit in Illinois?▾
The small claims court limit in Illinois is $10,000. Claims are filed in Small Claims Court (Circuit Court). You generally do not need an attorney for small claims.
How long do I have to file a mechanics lien in Illinois?▾
In Illinois, 4 months from completion for GCs; 90 days for subs. A Notice to Owner is required for subcontractors.
Do I need to send a demand letter before filing a lien in Illinois?▾
Subcontractors must serve a Notice to Owner within 60 days. A demand letter is standard practice for all parties.