Illinois certified payroll: the IDOL Certified Transcript of Payroll, monthly deadlines, and federal jobs

Illinois collects state certified payroll in one place: the Illinois Department of Labor's (IDOL) Certified Transcript of Payroll portal. Filing is monthly, and the Act spells out the worker data, down to each worker's race and veteran status.

The law and what it covers

The Prevailing Wage Act, 820 ILCS 130, covers all fixed works built or demolished by a public body, or paid for in whole or in part with public funds, including bonds, grants, and loans from the state or a local government. It reaches maintenance and repair, and the Act lists more: renewable energy projects under the Illinois Power Agency Act, utility contractors working in public rights-of-way, and others. The Act sets no minimum contract amount.

The Act's listed exclusions are narrow: work done directly by a public utility company, projects by the owner at an owner-occupied home, and soil and water conservation work on farmland done by the owner.

Covered workers are those employed directly on the site, plus those hauling materials and equipment to or from it. A supplier's own delivery drivers are excluded.

How certified payroll is filed

Where. IDOL's Certified Transcript of Payroll (CTP) portal. You sign in with an Illinois Public ID account. Each company needs its own login, so a bookkeeper filing for 2 contractors needs 2 accounts.

When. Section 5 of the Act requires a certified payroll for the preceding month no later than the 15th of each calendar month, and only for months in which construction occurred. A month with work on 1 day still gets a filing.

How. Manual entry in the portal, or an upload using IDOL's import template (the version for use starting July 1, 2025). Some rules from IDOL's FAQ and training deck:

• 1 project per file. Payroll is filed project by project.
• The template's day columns run Sunday through Saturday. If your week runs Thursday to Wednesday, enter your days in that order and total them; the column order can't change.
• On a biweekly payroll, split gross between the 2 weeks and report net on the second week.
• A worker in 2 classifications is entered once for each classification.
• "Non-prevailing wage hours" are hours the worker spent outside this project that week, including on other public works. IDOL requires them to check rates and overtime.
• Unless you check No Work Report, the portal requires a fringe benefit document. IDOL's Fringe Benefit Affidavit form lists each fund's name, address, sponsor, and administrator.

Signing. The Act requires a signed statement that you examined the records and they are true, that each worker got at least the prevailing rate, and that you know filing a false certified payroll is a Class A misdemeanor. In the portal you agree to the certification and type your name. IDOL emails a PDF and a CTP number to the contractor addresses on file; a prime or public body can ask you for that copy.

Subs file their own. IDOL recommends every contractor file its own certified payroll even if you have always handed it to the general contractor, because liability stays with each contractor.

Penalties. Failing to file brings a civil penalty of up to $1,000 for a first offense and up to $2,000 for a repeat within 5 years. Each month is a separate offense. Lack of knowledge of the rule doesn't count as mitigation. Willfully failing to file or filing a false payroll is a Class A misdemeanor.

Worker data the WH-347 doesn't carry

Section 5 lists the records you keep, and the certified payroll is a complete copy of them (starting and ending times may be left off the filing). The items in bold have no place on the WH-347:

• Name, address, and telephone number when available
• Last 4 digits of the Social Security number
• Gender, race, ethnicity, and veteran status
• Classification and skill level (apprentice or journeyman)
• Hours each day, and starting and ending times each day (kept, optional on the filing)
• Hourly wage, overtime, and fringe rates; gross and net pay
• Name and address of each fringe benefit fund, its plan sponsor, and its administrator

IDOL's FAQ says to ask workers for veteran status and race or ethnicity if you don't know them, because the Act requires it. IDOL's import template has worker columns for name, last 4 SSN, classification, race, ethnicity, gender, veteran status, a journeyman, apprentice, or foreman flag, daily prevailing and non-prevailing hours, rates, gross and net, and hourly pension, health, vacation, and training amounts. It has no column for a worker's home address or phone.

A contractor whose fringe contributions all go to jointly managed labor-management funds keeps only the first 8 items in section 5 (name through veteran status).

Address, phone, SSN, race, ethnicity, and gender are exempt from public records requests. IDOL publishes each worker's classification, skill level, hours, start and end times, wage, overtime, and fringe rates, and gross pay in its searchable database by the 16th of the month after the work.

The federal WH-347 is prohibited from carrying home addresses or phone numbers; it takes an individually identifying number such as the last 4 SSN digits. How the federal identifying number works.

Other state rules that affect payroll

Records. Keep them for 5 years from the last payment on the contract, on paper or electronically. On 7 business days' notice, make them available for inspection at a location in Illinois to the public body, IDOL, and law enforcement.

Posting. The contractor posts the prevailing rates for each craft at the job site. A contractor whose workers regularly visit its business location can post there, or give each worker a written notice of the rates.

Rates. IDOL sets rates by county and craft and revises them during the year; a revised rate applies to your contract. Holiday and overtime pay follow the published rates too.

Lower tiers. Each subcontractor must put a prevailing wage clause in every lower-tier subcontract, or give a written statement where there's no contract.

Jobs with federal money

The Act's definition of public works includes federal construction projects run by a public body when the state rate is equal to or greater than the federal rate for the same work. Whether IDOL's portal applies to your job comes down to the contract: IDOL says a contract stating it is subject to the Illinois Prevailing Wage Act means filing with IDOL, and a contract that mentions Davis-Bacon doesn't need an IDOL filing. If yours names both, ask the public body in charge of the project which filings it expects.

When both laws apply, pay at least the higher of the 2 rates for each classification and file twice. The state filing is monthly to IDOL with the Illinois data. The federal filing is a weekly WH-347 to the prime, with an identifying number and no address or phone. How the 4 largest states compare.

What CertifiedHours does here

CertifiedHours produces the federal WH-347, plus an LCPtracker upload file and a CSV, for federally funded work in Illinois. It does not file IDOL's Certified Transcript of Payroll, and it does not collect home addresses, phone numbers, or the demographic fields the Act requires. For state-funded work, file directly in IDOL's portal. Using the LCPtracker file.