- File monthly: certified payroll (the "Certified Transcript of Payroll") goes to the Illinois DOL online portal, every month you work a covered job.
- New fines (SB1344, eff. June 30, 2025): up to $1,000 for a first late filing, up to $2,000 for a repeat within 5 years.
- Each missed month is a separate violation — they stack.
- It's personal: failing to file, or willfully filing false records, is a Class A misdemeanor for the contractor, officer, employee, or agent.
- Debarment: four years, and on a guilty finding it can be immediate and without a hearing.
The thing that makes Illinois different
In most states, a certified payroll problem is a company problem. In Illinois, the law reaches the individual. A contractor — or an officer, employee, or agent of the contractor — who fails to file a certified payroll by the due date, or who willfully files a false certified payroll as to a material fact, is guilty of a Class A misdemeanor. That's a criminal classification attached to a person, not just a fine sent to an LLC. If you're the owner running the jobs and doing the paperwork at night, that person is usually you.
How you file: monthly, through the IDOL portal
Illinois requires contractors and subcontractors to submit certified payroll — formally the Certified Transcript of Payroll — at monthly intervals. The Illinois Department of Labor maintains an online Certified Transcript of Payroll Portal for this (under 820 ILCS 130/5.1 and PA 100-1177). You file for each month you perform work on a covered public works project. Public bodies can access a searchable database of what's been filed, so submissions are visible.
The new penalties (SB1344)
Effective June 30, 2025, Illinois added civil penalties specifically for filing certified payroll late:
- First violation: a fine of up to $1,000.
- Second or subsequent violation within five years: up to $2,000.
- Each month a certified payroll isn't submitted counts as its own separate violation — so a few missed months add up fast.
Failing to file by the due date, or willfully filing a false certified payroll, is a Class A misdemeanor — for the contractor, officer, employee, or agent.
A guilty finding can bring immediate debarment for four years without a hearing. Separately, two violations of the Act within a five-year period can lead to four-year debarment from public works.
And the underpayment penalties on top
If the Department finds you actually underpaid workers, you owe the difference between what you paid and the prevailing wage for all hours worked, plus a 20% penalty to the Department of Labor. Workers are also owed 2% of that penalty amount for each month the underpayment stays unpaid. So a classification or fringe mistake isn't just back wages — it's back wages plus a fifth on top.
How to stay clean
- File every month you work the job, through the IDOL portal — don't wait for the public body to ask.
- Classify by the work performed, not the job title, and pay the correct prevailing base + fringe.
- Don't skip months. A gap isn't neutral — each missed month is a fresh violation.
- Keep your records, and make sure whoever signs understands they're certifying as an individual.
Don't put your name on a late filing
PrevailComply tracks monthly Illinois deadlines, handles classification and fringe calculations, and prepares federal and Illinois certified payroll, helping reduce late-filing and underpayment risk. Tell us you're in IL and we'll prioritize it.
The bottom line
Illinois rewards being early and punctual: file the monthly transcript through the IDOL portal, pay the right prevailing wage, and never let a month slide. The free WH-347 generator handles your federal report, the WH-347 step-by-step guide walks the federal form, and the fine calculator shows what penalties stack up to. If you also work across state lines, see the prevailing wage software workflow, plus the California and New York guides.
This guide is general information for small subcontractors, not legal advice, and reflects Illinois Department of Labor guidance and recent legislation (SB1344) as of June 2026. Penalty amounts and procedures can change — confirm against current IDOL guidance and your project's documents, or contact the Illinois DOL.