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Certified payroll

Illinois certified payroll: how often, where to file, how long to keep

By the Public Works Desk Team · Last verified · How we check every number · Corrections

Source: Illinois Prevailing Wage Act, 820 ILCS 130/5 (retrieved 2026-11-13)

Illinois contractors file a certified payroll no later than the 15th of each month for the previous month,

only for months with construction on the job, through the Illinois Department of Labor's certified payroll database.

Records are kept for five years. A missed filing can cost up to $1,000, and up to $2,000 for a repeat, for each month.

  • State text quoted word for word
  • Checked November 13, 2026
A payroll clerk checks weekly payroll sheets against time cards at a desk in a winter site office, with a snowy school renovation outside the window.

Illinois at a glance

How oftenMonthly, by the 15th
Send toIDOL certified payroll database
System / formatIDOL online portal
Keep recordsYou keep: 5 years from the last payment
If you don'tUp to $1,000 (first) / $2,000 per month (repeat)

Worked example: a job running January to March 2027

Month with work on siteFile by
January 2027February 15, 2027
February 2027March 15, 2027
March 2027April 15, 2027

If no construction happens on the project in a month, no certified payroll is filed for that month.

What the law says

“no later than the 15th day of each calendar month file a certified payroll for the immediately

preceding month with the public body in charge of the project until the Department of Labor

activates the database created under Section 5.1 at which time certified payroll shall only be

submitted to that database”

Illinois Prevailing Wage Act, 820 ILCS 130/5 · retrieved 2026-11-13

“A certified payroll must be filed for only those calendar months during which construction on a

public works project has occurred.”

Illinois Prevailing Wage Act, 820 ILCS 130/5 · retrieved 2026-11-13

“for a period of 5 years from the date of the last payment made on or after January 1, 2014”

Illinois Prevailing Wage Act, 820 ILCS 130/5 · retrieved 2026-11-13

“is subject to a civil penalty, payable to the Department of Labor,

of up to $1,000 for a first offense and up to $2,000 for a second or subsequent offense no more

than 5 years after the first offense.”

Illinois Prevailing Wage Act, 820 ILCS 130/5 · retrieved 2026-11-13

“Each month in which a violation of this Section occurs shall constitute a separate offense.”

Illinois Prevailing Wage Act, 820 ILCS 130/5 · retrieved 2026-11-13

Step by step

  1. Close the monthCollect every worker's daily hours, classification, rates, fringe and fund details for the month.
  2. File in the IDOL portal by the 15thOnce the database is active, the payroll goes only to the database, not to the public body.
  3. Attach the signed statementIt avers the records are true, the rates meet the prevailing rate and that a knowingly false payroll is a Class A misdemeanor.
  4. Skip empty monthsNo construction that month on the project, no filing for that month.
Common mistakes
  • Leaving out the demographic fields (gender, race, ethnicity, veteran status) the Act lists.
  • Filing weekly federal WH-347s and assuming they cover the Illinois monthly filing.
  • Keeping records three years: Illinois requires five.
Federal money on the job? Illinois files Monthly, by the 15th, sent to IDOL certified payroll database. Illinois's 5 years is longer than the federal floor, which is to keep payrolls for at least 3 years after all the work on the prime contract is completed (29 CFR 5.5(a)(3)). Following Illinois's period covers both; on a federally funded job the weekly WH-347 goes in too.
Limits. Illinois's filing and recordkeeping rules here are for state public works, quoted from the statutes cited below. They do not replace the weekly WH-347 or the federal 3-year retention period (29 CFR 5.5(a)(3)) on a Davis-Bacon job. Penalty language is quoted, not computed.

Related

Other states

Sources