Federal Davis-Bacon is not the only rule that applies here. Certified payroll is a monthly Certified Transcript of Payroll, filed electronically through IDOL's CTP Portal, due by the 15th of the following month, a different format and cadence from the federal weekly WH-347. That runs on top of, not instead of, the federal WH-347 whenever the project also has federal money in it.
Illinois at a glance
- The Illinois Prevailing Wage Act (820 ILCS 130) sets the state's own prevailing wage requirements, enforced by the Illinois Department of Labor (IDOL).
- Certified payroll is a monthly Certified Transcript of Payroll, filed electronically through IDOL's CTP Portal, due by the 15th of the following month, a different format and cadence from the federal weekly WH-347.
- Only calendar months with actual construction activity need a certified transcript filed.
Illinois DOL: Prevailing Wage Act
What this means for your paperwork
Federal money on an Illinois job does not excuse the WH-347. It runs alongside whatever Illinois itself requires. Certified Payroll only handles the federal side: it checks the rate against the live SAM.gov wage determination and fills out the WH-347 with its Statement of Compliance. It does not file Illinois's own state form, so budget for that as a separate step if this project needs it.
How to file your Illinois CTP, step by step
The Certified Transcript of Payroll (CTP) is filed with the Illinois Department of Labor, not through Certified Payroll. You need a separate, free account with the state.
- Create an Illinois Public ID account at accounts.illinois.gov. IDOL recommends a shared business email, so the account does not depend on one person.
- Open the CTP Portal page, choose “Public Account”, and log in with that account.
- Submit each project separately. The Excel upload template (Full-CTP-Upload.xlsx) has a fixed column order and cannot combine several projects in one file.
- Enter every classification and its rate on its own line, with gross and net wages and any hours worked on non-prevailing-wage projects.
- Add the worker details the Act requires, including veteran status and race/ethnicity.
- Tick “state capital funds” if your contract is with a state agency.
- Submit by the 15th for the previous month. After the 15th you can no longer withdraw a submitted payroll to correct it.
A month in which no construction work happened on the project does not need a filing. Keep your underlying payroll records for at least five years from the last payment on the project. IDOL also states that a certified payroll alone is not enough to prove compliance with the Act.
WH‑347 vs the Illinois CTP
| Federal WH‑347 | Illinois CTP | |
|---|---|---|
| Applies to | Federally funded or assisted construction (Davis-Bacon) | Public works under the Illinois Prevailing Wage Act |
| Cadence | Weekly | Monthly |
| Filed with | The contracting agency | IDOL, in the CTP Portal |
| Format | Form WH‑347 | Portal entry or IDOL Excel template |
| State-only project | Not required | Required |
| Federal-only project | Required | Contracts that cite only Davis-Bacon do not file with IDOL |
If a project has both state and federal money, you file both.
What happens if you skip it
Under 820 ILCS 130/5, IDOL can fine a contractor who fails to file a certified payroll up to $1,000 for a first offense and up to $2,000 for a repeat offense within five years. Each month that goes unfiled counts as a separate offense. Separately, IDOL states that knowingly failing to file or willfully filing false records can bring a Class A misdemeanor charge and debarment from public works projects for four years. Violators must also pay workers the difference between the wage paid and the prevailing wage.
Frequently asked
Does Illinois have its own prevailing wage law?+
Yes. The Illinois Prevailing Wage Act (820 ILCS 130) sets the state's own prevailing wage requirements, enforced by the Illinois Department of Labor (IDOL).
Does Certified Payroll file Illinois's state certified payroll form?+
No. Certified Payroll files the federal WH-347 under Davis-Bacon, not Illinois's own state form. The moment an Illinois project is also federally funded, it checks the rate and fills out the WH-347 automatically. The state form is still a separate filing.
Do I report weeks with no work?+
No. IDOL says a week with no work does not have to be reported, and only calendar months with construction activity need a filing.
Can my subcontractor file through me?+
A subcontractor may hand payroll to the general contractor, but IDOL recommends that every contractor files its own. Liability stays with the individual contractor.
This is a general informational summary, not legal advice, and covers state-level rules only. Verify current requirements with Illinois's labor department or a qualified compliance advisor before relying on it.