How to Run a Construction Payroll Audit: A Step-by-Step Checklist for Trade Contractors
A construction payroll audit is not something most contractors think about until a Department of Labor (DOL) letter arrives or a workers' comp auditor starts asking for timecards. At that point, the scramble to locate records, verify classifications, and reconcile hours against pay stubs becomes the entire week's work. Running an internal payroll audit on a regular schedule prevents that scramble and catches errors before they compound into penalties, back-wage liability, or contract debarment.
The checklist below walks through the construction payroll review process step by step, covering everything an internal audit should verify before an external auditor ever asks.
A 6-Step Payroll Audit Checklist for Construction Contractors
Trade contractors face payroll complexity that most industries never encounter: prevailing wage rates that vary by project and jurisdiction, union benefit fund remittances, multi-state tax withholding, and certified payroll filings due weekly on federally funded work. A payroll audit for a construction company needs to account for all of that, not just whether paychecks were issued on time.
The steps below follow the order that makes the audit most efficient. Employee records come first because every downstream check depends on accurate worker data. Certified payroll validation comes near the end because a clean WH-347 is the product of accurate records, time data, and wage calculations working together.
Step 1: Verify Employee Records and Worker Classifications
Start the audit by confirming that every active employee has complete, current records on file. Incomplete or outdated worker records are the most common source of payroll errors on prevailing wage projects and the easiest to fix before they create problems downstream.
Verify the following for each worker:
Legal name, Social Security number, and current address
Employment classification (W-2 employee vs. 1099 independent contractor)
Trade classification and applicable wage determination (for prevailing wage projects)
Union membership status and local affiliation, if applicable
Active certifications, licenses, and apprenticeship registration
Worker classification errors are a top enforcement priority for both the IRS and the DOL. A worker classified as a 1099 contractor who should be a W-2 employee creates tax withholding liability, benefits exposure, and potential penalties across every pay period in which the worker was active. An HR and onboarding system that captures classification data at the point of hire and connects that data to payroll reduces the risk of stale or incorrect records persisting undetected.
Step 2: Reconcile Time Records Against Payroll
Pull time records for the audit period and compare them line by line against payroll registers. The goal is to confirm that hours worked match hours paid and that hours are assigned to the correct projects and cost codes.
Look for:
Discrepancies between hours recorded in the field and hours processed in payroll
Missing or incomplete time entries that were estimated or rounded
Hours assigned to incorrect projects or cost codes
Unapproved overtime entries that were paid without review
Paper timesheets are the most common source of reconciliation problems. When hours are written down days after the work happened and then manually re-entered into payroll, transcription errors and rounding are inevitable. A digital field tracking tool that captures clock-in/out times with GPS verification and task codes eliminates the gap between field data and payroll data because both pull from the same source.
Step 3: Audit Wage Rates and Overtime Calculations
Confirm that every worker was paid the correct rate for every hour worked during the audit period. On prevailing wage projects, the correct rate depends on the worker's classification and the wage determination attached to that specific project, not a flat company-wide rate.
Check each of the following:
Base hourly rates match the applicable wage determination or union agreement
Fringe benefit contributions (health, pension, vacation funds) were calculated and remitted correctly
Overtime was calculated at the correct threshold (40 hours under FLSA, or daily thresholds in states like California)
Workers who performed multiple classifications in one week had overtime calculated using the weighted average method, where required
Overtime miscalculation is one of the most frequently cited violations in DOL construction investigations. A worker who performs carpentry at one rate Monday through Wednesday and labors at a different rate Thursday and Friday requires a weighted average overtime rate, not a simple 1.5x on the last rate worked. A construction payroll system that applies union logic, prevailing wage lookups, and overtime rules automatically based on field data eliminates manual rate calculations and the errors that come with them.
Step 4: Review Tax Withholdings and Deductions
Verify that federal, state, and local tax withholdings were calculated correctly for each employee during the audit period. For contractors operating across state lines, multi-state withholding adds a layer that general payroll tools often handle poorly.
Confirm:
Federal income tax withholding matches current W-4 elections
State and local withholdings are applied based on the work location, not just the employee's home address
FICA (Social Security and Medicare) deductions are calculated on the correct wage base
Voluntary deductions (401k, health premiums, garnishments) are applied accurately and consistently
All quarterly filings (Form 941) reconcile against total wages paid and taxes withheld
Multi-state compliance is a particular risk for trade contractors who move crews between jurisdictions on a project-by-project basis. Some states require withholding based on where the work is performed, while others base it on the employee's residence. Incorrect state withholding can create both employer tax liability and employee filing headaches.
Step 5: Validate Certified Payroll Reports
For any project subject to Davis-Bacon or related prevailing wage requirements, pull the weekly certified payroll reports (WH-347) submitted during the audit period and verify them against the time and payroll records reviewed in the previous steps.
Confirm:
Every worker who performed covered work on the project appears on the certified payroll for that week
Classifications listed on the WH-347 match the wage determination attached to the contract
Wage rates (including fringe benefit contributions) meet or exceed the applicable prevailing wage
Hours reported on the WH-347 match the hours in the payroll register and the field time records
The Statement of Compliance is signed by an authorized individual
Discrepancies between certified payroll reports and source records are what trigger DOL investigative actions. A platform where field hours flow directly into certified payroll generation without manual re-entry reduces the chance that source data and reported data diverge.
Step 6: Confirm Records Retention Compliance
The final step is verifying that all records reviewed during the audit are being retained for the required period and stored in a format that can be produced on request.
Federal retention requirements under the FLSA include:
Payroll records (wage rates, hours, total pay, deductions): minimum 3 years
Supporting records (timecards, work schedules, wage tables): minimum 2 years
Certified payroll records on Davis-Bacon projects: minimum 3 years after project completion
DOL representatives can request these records at any time, and contractors must make them available for inspection. Failure to produce records on request can result in payment suspension on active contracts and potential debarment from future federal work. A centralized payroll reporting system that stores time data, wage records, and certified payroll filings in one searchable location makes retrieval straightforward rather than a multi-day excavation through filing cabinets and spreadsheets.
Build Certified Payroll Audit Readiness Into Your Workflow
Running a construction payroll audit after the fact catches problems. Building audit readiness into daily operations prevents them. Trayd captures field data, validates wage rates and classifications, processes payroll, and generates certified payroll reports in a single platform, so the records an auditor asks for are always clean, current, and retrievable. Schedule a demo to see how the system works for your operation.
Frequently Asked Questions
How often should a construction company run a payroll audit?
At a minimum, once per quarter. Contractors on prevailing wage projects benefit from monthly reviews of certified payroll accuracy, since errors compound quickly across weekly submissions and are harder to correct retroactively.
What records does the Department of Labor require contractors to keep for payroll?
Under FLSA regulations, payroll records must be retained for at least three years and supporting records (timecards, schedules) for at least two years. Certified payroll records on Davis-Bacon projects must be kept for three years after project completion.
What triggers a Department of Labor payroll audit in construction?
Common triggers include worker complaints, discrepancies in submitted certified payroll reports, random selection, or a contractor's history of prior violations. Construction is among the most frequently audited industries for wage and hour compliance.
What is the most common payroll error found in construction audits?
Overtime miscalculation is one of the most cited violations, particularly on projects where workers perform multiple classifications in one week and the weighted average overtime rate is not applied correctly.
How do I prepare for a certified payroll audit?
Ensure WH-347 reports match source time records and payroll registers, verify worker classifications against the applicable wage determination, confirm fringe benefit contributions were remitted correctly, and store all records in a format that can be produced within 72 hours of a request.
Can payroll software help with construction payroll audit preparation?
Yes. A construction-specific payroll system that connects field time data to payroll processing and certified payroll generation maintains an audit trail automatically, reducing the manual reconciliation work that makes audit preparation slow and error-prone.
References
U.S. Department of Labor. "Fact Sheet #21: Recordkeeping Requirements Under the FLSA." dol.gov
U.S. Department of Labor. "Fact Sheet #66: The Davis-Bacon and Related Acts." dol.gov
U.S. Department of Labor. "Investigative Procedures and Remedies on Davis-Bacon Contracts." dol.gov
U.S. Department of Labor. "WH-347 Instructions." dol.gov
