ItemizationEach damage item + cost
The statement should identify the alleged damage and repair/replacement cost.
Receipts unavailable through no fault of landlordVerified explanation + other evidence
Subsection (b) provides a specific alternative when receipts cannot be produced through no fault of the landlord.
If the landlord uses an estimate
If estimated cost is given, Illinois requires paid receipts or copies within 30 days after the statement showing the estimated cost was furnished.
If the landlord performs the work
The statute permits the reasonable cost of the landlord’s own labor to repair or replace tenant-caused damage.
Check local law too. Illinois statewide law is the baseline. Chicago and other municipalities can add renter protections, deadlines or remedies.