75%+ of Workers Comp Premium Audits Result in Higher Bills — Here's Why

How Workers Comp Premiums Work

Unlike most insurance lines where you pay a fixed annual premium, workers compensation premiums are estimates. At the start of each policy year, your carrier estimates your premium based on your projected payroll and the classification codes assigned to your employees. At the end of the year, the carrier audits your actual payroll to see what the premium should have been. If your actual payroll was higher than projected, you owe the difference. If it was lower, you may receive a return premium. Because businesses routinely grow, add employees, and expand scope during the year, actual payroll almost always exceeds the initial projection — which is why the majority of audits result in additional premium owed.

The Three Most Common Causes of Audit Surprises

1. Underreported Payroll at Inception: Many businesses, especially those quoting workers comp for the first time, underestimate their projected annual payroll. Seasonal workers, variable overtime, and new hires added during the year all contribute to higher actual payroll than originally reported.

2. Misclassified Employee Categories: Workers comp uses hundreds of class codes, each with its own rate per $100 of payroll. A clerical employee (class code 8810) costs dramatically less than a roofing worker (class code 5551). When employees perform duties across multiple classifications, auditors may reclassify them into higher-rated codes based on their actual job duties — increasing premium significantly.

3. Included Subcontractors: If you hire uninsured subcontractors, their payroll is typically added to your audit as if they were employees — because you're exposed to their injuries under California law. Always collect certificates of insurance from every subcontractor before work begins.

What the Auditor Actually Checks

Workers comp auditors typically request:

• Quarterly payroll tax returns (Form DE 9 in California) • State and federal payroll filings (W-2s, W-3s, 1099s) • Certificates of insurance from all subcontractors • General ledger or check register showing payments to subcontractors • Description of duties for each employee class code • Officers and owners compensation records

The auditor's job is to ensure that the carrier collected the right premium for the risk that was actually on the books — not to create additional charges arbitrarily. Most audit surprises are legitimate corrections to initial underestimates.

How to Prepare and Minimize Surprises

The best strategy is to track actual payroll throughout the year and notify your agent whenever your actual payroll is significantly outpacing your projection. Most carriers allow you to submit a payroll correction mid-term that adjusts your deposit premium before the audit, preventing a large lump-sum bill at year end.

Additionally:

• Maintain clear job duty descriptions for each employee that support the classification codes assigned at inception. • Keep all subcontractor certificates of insurance on file and verify they haven't lapsed. • If any employee's role changes significantly during the year, notify your agent — class code changes mid-term are easier than fighting them at audit. • Review your audit worksheet carefully. Errors do occur, and you have the right to dispute audit findings you believe are incorrect.

What Happens If You Dispute an Audit

If you believe the auditor misclassified employees, included subcontractors who had their own coverage, or made computational errors, you have the right to dispute the audit findings. The process involves:

1. Requesting the auditor's worksheet showing how classifications and payrolls were determined. 2. Providing documentation supporting your alternative classification — job descriptions, licenses, certificates of insurance. 3. Working with your agent and, if necessary, the carrier's audit review department.

Disputes must typically be initiated within a defined period after the audit completion. Act quickly if you believe an error has occurred.