Illinois Late Fee Calculator
Your late fee
$62.50
Paid 12 days late; the lease has no grace period.
- Days past due
- 12 days
- Grace period ends
- No grace period
- Earliest fee date
- October 20, 2026
- Lease late fee
- 5% of $1,250.00 = $62.50
- Rent + late fee
- $1,312.50
Illinois: 765 ILCS 705 to 755; 735 ILCS 5/Art. IX contains no late fee provision, so there is no legal cap or waiting period to apply; only your lease terms count.
Late rent notice builder
[Your name or company]
Date: October 31, 2026
To: [Tenant name]
[Rental property address]
Re: Overdue rent for [Rental property address]
Dear [Tenant name],
This letter is a reminder that the rent of $1,250.00 for [Rental property address] was due on October 19, 2026. As of October 31, 2026, $1,250.00 of it is still unpaid (12 days past due).
Your lease provides for a late charge, which comes to $62.50.
Amount now due
- Unpaid rent
- $1,250.00
- Late charge
- $62.50
- Total
- $1,312.50
Please pay $1,312.50 at your earliest opportunity.
If this letter crossed with your payment, please disregard it.
Regards,
[Your name or company]
Statutory legal rate on written instruments and money wrongfully withheld when no rate is agreed.
Late fee breakdown
- Interest owed
- —
- Daily rate
- —
- Total (invoice + interest)
- —
Still unpaid? Generate a formal demand letter
Interest at 5% a year
| Invoice amount | 30 days late | 60 days late | 90 days late |
|---|---|---|---|
| $1,000.00 | $4.11 | $8.22 | $12.33 |
| $5,000.00 | $20.55 | $41.10 | $61.64 |
| $10,000.00 | $41.10 | $82.19 | $123.29 |
Maximum late fee in Illinois — written B2B contracts
No statutory cap
Basis: 815 ILCS 205/4(1)(a),(c).
About this page
Mobile home parks in Illinois
This covers mobile home park or manufactured home community leases only: such a lease cannot permit a penalty fee for late rent unless the tenant is given at least 5 days past the due date to make the payment.
Sec. 12. Lease prohibitions. No lease hereafter executed or currently existing between a park owner and tenant in a mobile home park or manufactured home community in this State shall contain any provision: (a) Permitting the park owner to charge a penalty fee for late payment of rent without allowing a tenant a minimum of 5 days beyond the date the rent is due in which to remit such payment;
Illinois rent late fee law
Illinois has no statewide late fee cap or grace period for ordinary residential leases in its landlord and tenant acts; mobile home parks have a separate rule.
Read in full for this check: Illinois Compiled Statutes, chapter 765, the Landlord and Tenant acts (765 ILCS 705 to 755), and 735 ILCS 5/Article IX (Eviction). Official source, read from the copy archived on 2026-09-11 · checked .
Before you send the late rent notice: it is a reminder letter about overdue rent and a late charge, not an eviction notice. A notice to pay rent or quit is a separate document, and Illinois has its own rules for it. Nothing on this page is legal advice.
What Illinois law says about invoice interest
Creditors shall be allowed to receive at the rate of five (5) per centum per annum for all moneys after they become due on any bond, bill, promissory note, or other instrument of writing; on money lent or advanced for the use of another; [...] and on money withheld by an unreasonable and vexatious delay of payment.
9% nominal cap, but any loan to a corporation and any business-purpose loan may bear any agreed rate. Ordinary B2B credit is effectively uncapped.
Not legal advice. Figures were last verified on the date shown; check the cited statute before charging a late fee.