Last updated: October 2026

Workers comp audit: what happens, how to prepare, how to fight the bill

Your workers compensation audit is not optional and it is not a formality. In Texas, every workers comp policy is subject to a final payroll audit, and the carrier uses the results to adjust your workers comp premium retroactively.

How the workers compensation audit works

When you purchase a workers comp policy, the carrier estimates your annual premium based on the payroll numbers you provide. The carrier assigns class codes to your business, applies the rate per $100 of payroll for each code, and calculates your estimated premium. You pay that estimated premium throughout the policy year, either annually or in monthly installments.

If your actual payroll was higher than estimated, you owe the difference in premium. If it was lower, you get a credit. If employees were misclassified into a lower rate class code, the auditor moves them to the correct code and charges the higher rate retroactively for the entire year.

What the auditor actually looks at

A workers compensation audit is a payroll audit. New York's State Insurance Fund asks for your payroll book, your quarterly 941 filings, New York's NYS-45 returns, and your W-2, W-3, 1099 and 1096 forms. It also asks for your cash book, general ledger, income tax returns, subcontractor certificates of insurance, and contracts and invoices.

Auditors look beyond W-2 wages. In Texas, auditable payroll includes commissions, bonuses, overtime pay, holiday and vacation pay, and the value of meals and lodging received as part of pay. In New York and Texas, overtime counts only at the straight time rate, as long as your records show overtime pay separately for each employee and totaled by classification. If you paid an employee $20 per hour base and $30 per hour overtime, the auditor uses $20 for the overtime hours, not $30.

In New York, payments to uninsured subcontractors get added to your auditable payroll. If you hired a 1099 contractor who does not carry their own workers comp insurance, the auditor treats that payment as if it were payroll to your own employee. A $50,000 payment to an uninsured sub working under a construction class code rated at $12 per $100 adds $6,000 to your audit bill. The fix is to collect a workers comp certificate of insurance from every subcontractor before they start work.

The class code reclassification trap

Workers comp class codes determine your rate per $100 of payroll. Auditors reclassify employees when the job duties described on the policy do not match the actual work being performed. A construction company that lists a project manager as clerical (8810) when that person spends half their time on job sites (5606, contractors executive supervisors) will see that employee reclassified at the higher rate for the full policy year.

The gotcha is the payroll division rule. In Texas, an employee who interchanges between operations in more than one classification has their entire payroll assigned to the highest rated classification representing any part of their work. Clerical code 8810 applies only to employees doing office work exclusively, and if a clerical employee has any other duty, their total payroll goes to the highest rated classification they are exposed to. An employee who splits time between office work and field work is not split proportionally.

Construction is one of the exceptions. Texas allows an individual employee's payroll to be divided between construction classifications, but only with accurate records of the work each employee performed, and an estimated or percentage allocation is not permitted. New York's State Insurance Fund also requires the separation to rest on actual time worked in each code, not on percentages.

Your experience modification rate multiplies whatever the class code rate produces. An EMR of 1.15 on a $50,000 base premium adds $7,500 per year. If the audit reclassifies employees into higher rated codes AND your EMR is above 1.0, both multipliers stack.

How to prepare before the auditor calls

Run your own internal audit first. Pull your quarterly 941 filings and add up total wages reported to the IRS. Compare that number to the total payroll you reported to your workers comp carrier at policy inception. Calculate the difference yourself so you know the number before the auditor tells you.

Review every employee's class code assignment against their actual job duties. Read the class code descriptions in your state's workers comp manual. A "driver" could fall under 7380 (drivers, chauffeurs and their helpers), 7219 (trucking) or 7197 (parcel or package delivery). If any employee's duties changed during the policy year, document when the change occurred and the actual time spent in each role.

Gather certificates of insurance for every subcontractor you paid during the policy year. Organize them by sub name with the payment amounts.

Separate overtime premium pay from straight time pay in your records. Provide a clear breakdown showing base rate hours and overtime premium hours separately.

New York's State Insurance Fund lists the documents it needs in an appointment letter. After a missed appointment, insufficient records, or no response, it may conduct an estimated payroll verification instead, which can produce a higher premium than a proper verification would have.

How to dispute the audit results

Oregon's Department of Consumer and Business Services lists the common audit disputes as payroll amounts, worker classifications, and whether certain workers should have been included. Its first step is to contact your insurer or agent and explain exactly what you disagree with. If that does not resolve it, Oregon's Small Business Ombudsman for Workers' Compensation can contact the insurer for you, and formal appeal options follow. Oregon sets a 60 day deadline, and missing it can limit your options. Keep copies of payroll records, contracts and audit documents, because they are often needed to resolve a dispute.

For a class code dispute, you need the official class code description, a written description of the employee's actual duties, and ideally a job description or organizational chart showing how the role functions. If the auditor classified your marketing coordinator as a salesperson because they occasionally visit client sites, the distinction between inside office work and outside sales becomes the argument.

Avoiding surprises on the next audit

Switch to pay as you go workers comp if your payroll fluctuates significantly. New York's State Insurance Fund offers PayGo, which aligns premium to your payroll each pay period, with payroll reported weekly, biweekly or monthly. The payroll verification at the end of the policy year still happens, and the reported payroll feeds into it, so premium no longer has to be estimated. The fund describes PayGo as keeping pace with the month to month flows of seasonal business.

Update your carrier midyear if you hire new employees, change job roles, or add subcontractors.

Keep a running file of subcontractor certificates organized by vendor name and payment amount. When the auditor calls, hand them the complete file.

Review your workers comp premium calculation annually against your payroll provider's reports. The carrier should be using the same total payroll numbers your provider reports. If the two do not match, find the discrepancy before the auditor does.

This is not legal or financial advice. Consult a qualified professional for your specific situation.