## Workers Comp Payroll Audit: What California Contractors Need to Know
At the end of every workers comp policy year, your carrier conducts a payroll audit to reconcile your actual payroll against the estimate you provided when the policy started. This audit determines whether you owe additional premium or get a refund.
### Why Audits Happen
Workers comp premiums are calculated based on estimated payroll at the start of the policy. If your actual payroll was higher than estimated, you owe more premium. If it was lower, you get a refund or credit.
### What the Auditor Looks For
A workers comp auditor will typically request:
- **Payroll records** — quarterly payroll tax returns (DE 9/DE 9C), W-2s, 1099s
- **Certificates of insurance** from subcontractors
- **Contracts** for major projects
- **Job descriptions** for employees
### The Subcontractor Trap
This is where many California contractors get surprised. If you use subcontractors who:
- Are not licensed
- Do not have their own workers comp policy
- Cannot provide a valid COI
...your carrier may include their labor costs in your payroll, dramatically increasing your audit bill. Always collect COIs from every subcontractor before they start work.
### How to Prepare for a Workers Comp Audit
1. **Keep organized payroll records** throughout the year
2. **Collect COIs from all subcontractors** and keep them on file
3. **Classify employees correctly** — a project manager is not a field laborer
4. **Track overtime separately** — overtime premiums are generally excluded from WC payroll calculations
5. **Document owner exclusions** — if you are an owner excluded from coverage, document this properly
### Avoiding a Surprise Audit Bill
The Appropriate way to avoid a large audit bill is to use **pay-as-you-go workers comp**, which adjusts your premium each pay period based on actual payroll. This eliminates the year-end reconciliation surprise.
### Get Help with Your Workers Comp
Asena Capital Insurance Services helps California contractors navigate the audit process and find carriers with the most favorable audit procedures.
**Call (858) 925-9555** or [get a quote online](/get-workers-comp-quote).