5 certified payroll mistakes DOL loves to find

Ran into a GC at a trade show last month who'd just survived a DOL audit. Took six months and cost him $40k in back wages for a mistake his sub made. He hadn't even reviewed the sub's reports. That's what got me writing this one.

Certified payroll isn't complicated in theory. Pay workers the prevailing wage, track it on a WH-347, submit weekly. In practice, five mistakes account for the overwhelming majority of audits, and none of them require bad intent to trigger.

1. Worker misclassification. According to DOL enforcement data, 40% of prevailing wage violations stem from misclassification alone. The DOL doesn't care what your internal job title says — they care about the work actually being performed. A carpenter doing carpentry needs to be classified as a carpenter, even if your payroll system calls them a general laborer. One Pennsylvania contractor learned this at a cost of $85,000 after classifying skilled tradespeople as general laborers on multiple federal projects.

2. Fringe benefit errors. This is the one that surprises people. According to BlueWave HR's 2026 compliance guide, the most common reason for DOL audits isn't deliberate underpayment. It's incomplete or inconsistent fringe benefit documentation. The prevailing wage has two components: base rate plus fringes. Both have to be exact, and you need documented proof that fringe dollars went to qualifying benefit plans. A miscalculation of $0.10 per hour across a crew of 20 over six months becomes a $5,000-plus back-wage liability before penalties are even added.

3. Outdated wage determinations. Prevailing wage rates change by location, by project type, and now more frequently after the 2023 Davis-Bacon regulatory overhaul. Running payroll against last year's determination is a straight path to underpayment findings. Pull the current determination before the first payroll runs on any covered project, not after mobilization.

4. Late or missing submissions. The WH-347 is due within seven days after each pay period closes. Miss it, and you're looking at withheld contract funds. Miss it repeatedly, and Payroll4Construction notes that some states have calculated $7 million in late submission fines in a single fiscal year. Auditors also treat gaps in your submission record as red flags — if week 14 is missing, they assume you were hiding something.

5. Ignoring your subcontractors' reports. As a prime contractor, you are legally on the hook for every sub's payroll errors — even ones you never reviewed. Federal agencies hold prime contractors responsible for subcontractor compliance, full stop. One sub's misclassification creates exposure for the entire project team. That means collecting, reviewing, and retaining sub reports isn't optional paperwork. It's your liability management.

People treat certified payroll audits as a compliance problem. They're actually a lottery problem with terrible odds on the prize side.

The DOL's Wage and Hour Division has 611 investigators responsible for enforcing wage laws across a workforce of over 120 million people. That's one investigator per 278,000 workers. Your weekly probability of being audited is genuinely tiny. Most contractors know this, which is why so many treat certified payroll as a box-ticking exercise.

The problem is what happens when you do get hit. Back wages. Compounding daily interest under federal statute. Civil penalties up to $13,508 per violation, per pay period, across every employee on the project. And if a contracting officer determines your inaccurate reports were knowing, the False Claims Act kicks in — which triples the original underpayment as damages. All of this can reach back three years. Three years of weekly payroll on a multi-project operation is a lot of exposure.

The lottery is rare. The jackpot is the contractor's entire pipeline.

WH-347 deadline: September 30, 2026 The old certified payroll form stops being accepted in six weeks. The updated version adds expanded fringe benefit fields and apprentice documentation. eMars has a clear walkthrough of what changed.

Michigan's reinstated prevailing wage law Michigan brought back prevailing wage requirements in 2024 for state-funded projects over $250,000. It takes effect for projects bid after July 1, 2025, covering an estimated $3.2 billion in annual state construction spend. If you're working there, your old rate tables won't cut it. Full state-by-state breakdown at Buildermuse.

Nevada expands to P3 projects Nevada now covers construction under public-private partnerships and any project receiving state financial incentives over $500,000 — capturing the significant data centre and battery plant work under state incentive programmes. Same Buildermuse piece covers it.

New York's e-filing mandate is live Paper certified payroll is no longer accepted in New York. All contractors and subcontractors must submit through the NYS DOL portal. If your payroll system doesn't export in the right format, that's a compliance gap today, not eventually. Lumber's 2026 NYS guide explains the portal requirements.

DOL's official WH-347 instructions The source document for what goes in every column. Worth bookmarking and sharing with whoever fills out your forms. Direct from DOL.gov.

That GC from the trade show told me the audit wasn't the worst part. The worst part was calling his sub to explain what had happened. Six weeks to the old WH-347 deadline. Good time to check your forms.