Quick answer: A premium audit is the carrier's year-end check of what your business actually did during the policy term, compared with the estimate the premium was built on. Workers' comp is priced per $100 of payroll by class code, and contractor general liability is usually priced on payroll, sales, or the cost of subcontracted work, so any of those running higher than estimated produces an additional premium bill. For contractors, the biggest surprises usually come from subcontractors: a sub with no certificate on file, an expired one, or limits below what your carrier accepts is typically treated as if their workers were your employees. Misclassified payroll, overtime that was not recorded separately, and owners or officers included at state payroll amounts add more. Most of it is preventable with clean records, a certificate for every sub covering the whole time they worked, and mid-year updates to your exposure. Aiden Risk, an AI-native independent commercial insurance broker, pairs year-round AI monitoring with a licensed broker who acts on each change, so your estimate tracks reality before the auditor arrives.
The timing makes these bills sting. Audits happen after the policy expires, so the invoice lands months after the work was done and the job was priced. It is money you did not bid into the project and cannot pass on.
What a premium audit is, and why contractor policies are auditable
Some policies are written on exposures that move during the year: payroll, sales, or the total cost of work you sublet. The carrier charges a deposit premium on estimates, then reviews your records after expiration and adjusts the premium up or down. Nationwide's premium audit page describes exactly this: premium is based on estimated exposures such as payroll or gross sales, and the audit determines your actual exposures once the policy period ends. For contractors, workers' comp and general liability are the policies that usually get audited.
Workers' comp premium is payroll divided by 100, times the rate for each class code, times your experience mod, as Nationwide's premium guide lays out. Because the rate attaches to the code, a dollar of roofing payroll costs far more than a dollar of clerical payroll, so classification matters as much as the total. Our mid-market workers' comp guide explains the mod.
General liability can be rated on payroll, gross sales, or total cost, depending on the class and carrier. Total cost is the usual basis for subcontracted work, and the ISO definition summarized by the Big I covers all labor, materials, and equipment in the sublet work, plus fees and bonuses, typically rated per $1,000. Your contractor general liability declarations show which basis applies to each class.
Why your audit bill jumped: the usual causes
Payroll or revenue grew
Estimate $1.2 million of field payroll, run $1.6 million, and the audit charges the extra $400,000 at your class rates. Tell your broker when you add a crew or land a large contract.
Misclassified payroll and undocumented splits
Auditors classify by duties, not titles. ICW Group's audit checklist asks for a list of employees in the clerical and outside sales codes with a short description of what each one does, because those codes are rated far below field work. Nationwide does not let an employee's payroll be split between a construction code and an office or sales code, so an estimator who also runs crews is a field employee.
Splitting one employee's pay between construction codes, say a carpenter who also does concrete, is generally allowed only with records. Nationwide permits it for construction or erection work if proper records are kept, and says percentage breakdowns will not be accepted. Without original time records, the result can be harsh: Washington's state-fund rule, WAC 296-17-31017, assigns all of a worker's unrecorded hours to the highest-rated classification the worker was exposed to.
Uninsured subcontractors charged as your employees
If a sub cannot show workers' comp coverage, most state laws can hold you responsible for injuries to its employees, so Nationwide says the sub's payroll may be added to your premium base. Nationwide also asks for subcontract costs split between labor and materials and does not accept percentage breakdowns. Under NCCI's Basic Manual rule on subcontractors, as applied in a 2013 Tennessee insurance commissioner's order, when the sub's payroll records are not produced, the full subcontract price for work performed during the policy period can be used. A $200,000 lump-sum framing sub with no certificate and no payroll records could therefore add up to $200,000 of framing payroll to your audit.
Subs who had insurance, but not on paper
- No certificate on file. The auditor works from documents, not your memory.
- Dates that do not cover the work. AmTrust's subcontractor guidance says certificate dates must span the entire time the sub worked, and if the sub's policy expires mid-job you need a new certificate showing the renewal.
- Limits below your carrier's minimum. Requirements vary by carrier. Nationwide treats a sub as adequately insured only with at least $1,000,000 per occurrence, $2,000,000 general aggregate, and $2,000,000 products-completed operations aggregate, and charges payroll for anything less.
- Certificates that do not match the payee. AmTrust advises that the sub's name on the certificate be exactly the name on your checks. A certificate with missing or unclear details invites the same scrutiny.
1099 workers who look like employees
A 1099 does not settle employment status. The IRS common-law test weighs behavioral control, financial control, and the type of relationship, and auditors ask similar questions. Nationwide says that, depending on state law, a person called a subcontractor who has no employees of their own and whose duties closely resemble your employees' may be treated as your employee for audit purposes. A one-person sub who works only for you, uses your tools, and follows your schedule is the classic example.
Owners and officers
Officers are generally included in workers' comp unless they have been excluded under your state's rules, usually by a written election or endorsement on file. In California, for example, AmTrust's audit notice explains that an officer must meet an ownership threshold and file a waiver to be excluded, or the officer's payroll goes into the final audit. Included executive officers are counted between a weekly minimum and maximum, as Insurance Journal's summary of audit rules explains, and each state sets its own amounts for sole proprietors and partners who opt in. Rules vary by state and entity type, so confirm elections in writing at renewal.
Overtime with no separate record
Overtime is payroll, but in most states the premium portion is excluded: one-third of time-and-a-half pay and one-half of double time, per Insurance Journal's summary. The catch is documentation. Nationwide deducts the excess over straight time only if your records show overtime separately by employee, totaled monthly and quarterly, and notes the deduction does not apply to workers' comp in Pennsylvania and Delaware.
Casual labor and cash payments
Day laborers paid in cash or by check outside payroll are still remuneration. ICW Group calls a report of payments to off-payroll entities and individuals perhaps the most important audit document, and asks for the general ledger, check register, cash disbursements, and payments made through Venmo, Zelle, or other cash apps. If a payment is not documented as going to an insured sub, expect it to be added to your payroll.
Why you are charged for insured subcontractors on your GL audit
On workers' comp, a valid certificate usually takes the sub off your audit. On GL, many policies still charge for insured subs, just on a different basis.
The reason is that a general contractor keeps some liability for a sub's work even when the sub is insured. Nationwide notes you may be responsible for your subcontractors' legal liability, and if the sub's coverage fails or runs out, the claim can come back to you. The ISO rules summarized by the Big I charge adequately insured subs under the subcontracted-work classification on a total cost basis, while inadequately insured subs are charged under the classification for the work they performed, with payroll as the basis.
How much you pay depends on your carrier's rating plan and policy wording. A sub can be rated as inadequately insured on GL if the certificate is missing, limits are below your carrier's requirement, the policy period does not overlap the work, or the additional insured endorsement your contract required is not in place. See the additional insured problem for why endorsements matter beyond the audit.
Workers' comp rates are falling. Why isn't your bill?
In several states we serve, workers' comp pricing is down. Florida approved an overall 6.9 percent rate decrease for new and renewal policies effective January 1, 2026, its ninth straight annual cut. Arizona's rates fell 6.7 percent effective January 1, 2026, the twelfth straight year of decreases. The Texas Department of Insurance accepted NCCI's advisory loss cost filing for policies effective on or after July 1, 2026, an overall average 3.8 percent decrease in loss costs.
Those are statewide averages, and in Texas they are loss costs that each carrier builds its own rates on. None of them changes the audit mechanics above. A contractor whose rate fell 6.9 percent but who picked up $200,000 of uninsured sub payroll in a high-rated code still sees a bigger bill.
Common audit adjustments and how to prevent them
| Cause | What the auditor typically does | How to prevent it |
|---|---|---|
| Payroll or sales grew past the estimate | Charges the actual figure at your class rates | Report growth mid-term so the deposit premium is revised |
| Sub with no certificate | Adds the sub's labor to your payroll, using a percentage of the contract price if labor is not broken out | Collect a certificate before the sub starts work |
| Sub's policy lapsed during the job | Treats the uncovered period as uninsured | Track expiration dates and request renewals early |
| Sub's GL limits below the carrier's minimum | Treats the sub as inadequately insured and charges payroll | Put minimum limits in the subcontract and check them |
| Required additional insured endorsement missing | May rate the sub as inadequately insured, depending on policy wording | Require the endorsement itself, not just a box on the certificate |
| Lump-sum invoices from uninsured subs | Can use the full subcontract price when the sub's payroll is not documented | Ask subs for invoices that split labor and materials |
| One employee in two trades, no time records | Can assign all their payroll to the higher-rated code | Keep original time records by employee and operation |
| Overtime not shown separately | Includes the full overtime amount | Break out overtime pay by employee, with monthly and quarterly totals |
| Officer you thought was excluded | Includes them at the state payroll amount | Confirm exclusion endorsements at renewal |
| Cash or 1099 labor | Adds it to your payroll | Run labor through payroll or hold certificates for true subs |
| Wrap-up job payroll mixed in with other work | Cannot separate the wrap-up exposure from the rest | Keep wrap-up project records and payroll separate |
How to prepare before the auditor arrives
Carriers publish what they want. AmTrust's audit checklist includes payroll records, Form 941 and state unemployment returns, 1099s, payments to subcontractors, sub certificates, payments to cash labor, and job cost records, and Nationwide also asks for W-2s, QuickBooks reports, and profit and loss statements. Florida's audit rule, 69O-189.003, names subcontractor certificates among acceptable records and calls for physical audits on many construction-class policies.
- Build a certificate file for every sub. Get one before the sub starts and at each new project, and set a reminder ahead of each expiration date, as AmTrust suggests, so you can collect the renewal. Check dates, limits, carrier, and policy numbers. Our certificate of insurance guide covers what to look for.
- Pull a subcontractor payment report by sub, with dates and totals. Nationwide lists QuickBooks reports among the documents it commonly requests.
- Match every paid sub to a valid certificate, and chase the missing ones now, not after the bill.
- Sort payroll by class code, with time records behind any split.
- Break out overtime by employee where your state allows the deduction.
- Confirm officer and owner status and that any exclusion elections or endorsements exist.
- Gather labor and material invoices for any uninsured subs.
- Reconcile to your policy estimate, and have someone who knows the operations present for the audit.
What to do when you disagree with the audit
Move quickly. Nationwide asks policyholders to contact its audit department immediately if they find discrepancies, and billing changes take effect 14 days after it updates the policy. ICW Group likewise tells policyholders to review their audit worksheet carefully and contact the auditor right away if anything is wrong.
- Request the audit worksheet. You need payroll by class, every sub treated as uninsured, and every officer included.
- Check classifications against actual duties, and look for payroll pushed to a higher code because split records were missing.
- Check subcontractor treatment. For each sub rated as uninsured, find out why: no certificate, wrong dates, short limits, or a missing endorsement.
- Submit what was missing and ask for a revised audit in writing.
- Escalate if needed. In NCCI states, once you have made a reasonable attempt with the carrier, you can ask NCCI for help with manual-rule disputes such as class codes or payroll allocation, as Connecticut's insurance department describes.
State processes differ. In Texas, carriers assign class codes, either side can ask NCCI for help if they disagree, and doing so does not stop the policyholder from pursuing other legal remedies, per TDI's notice on NCCI Item 02-TX-2019. In California, you file a complaint and request for action with the insurer, then can appeal its written decision to the Department of Insurance's Administrative Hearing Bureau, generally within 30 days, using the CDI policy appeal form. Rules and deadlines change, so confirm the current process with your broker, carrier, or counsel.
Do not ignore the audit. Under NCCI's audit noncompliance charge rule, adopted in many states, a carrier that attached the endorsement at inception can charge up to two times your estimated annual premium after two documented attempts to get your records, and may cancel where state law allows. The charge is refunded or credited if you later complete the audit.
How to stop the surprise next year
- Set honest estimates at renewal. A low estimate makes the quote look cheaper and the audit more painful. Our renewal checklist covers what to bring.
- Consider pay-as-you-go workers' comp. Pie Insurance bases monthly premium on actual payroll rather than an estimate, which it says helps avoid an additional bill after the annual audit if you grow during the year. A final audit is still required, as ICW Group notes, and pay-as-you-go does not fix sub or classification problems.
- Update exposure mid-term. New hires, a new trade, a new state, or a big contract are reasons to call your broker during the year.
- Run a sub compliance process. Write limits, additional insured, and waiver requirements into every subcontract, collect certificates before work starts, and track expirations.
- Sort out wrap-ups before the job starts. Nationwide asks for OCIP and wrap-up project records at audit. Keep that payroll separate, and confirm with your broker how your own policy treats the wrap-up work.
Claims drive the other half of your comp cost through the mod; see how claims history affects your rates.
How Aiden Risk Prevents Surprise Audit Bills
Every cause above traces back to the same gap: the policy was written on one set of facts and the auditor found another. Aiden Risk closes that gap in one place, pairing an AI risk engine built for commercial insurance with a licensed broker on every account, from placement through renewal and the audit itself.
| The problem | How Aiden Risk solves it |
|---|---|
| Payroll or revenue grew past the estimate | Our AI monitors your risk year-round, and a licensed broker acts on every change it flags, including correcting your payroll estimate mid-term when you add a crew or land a big contract. |
| Payroll landed in the wrong class code, or splits had no records | Your broker reviews class codes against actual duties before binding and walks through the audit worksheet with you to catch payroll pushed into a higher-rated code. |
| Uninsured subs charged as your employees | Your broker advises on the insurance clauses to put in every subcontract and reviews which subs the auditor treated as uninsured, so missing proof can be submitted. |
| Subs with no certificate, wrong dates, short limits, or missing endorsements | The free COI checker grades a certificate against the contract from a few answers and flags gaps such as a missing additional insured, no waiver of subrogation, or short limits; your broker reviews the requirements in your subcontracts. |
| 1099 workers who look like employees | Your broker reviews how off-payroll workers are likely to be classified at audit and advises on the coverage to require from true subcontractors. |
| Owners and officers included when you assumed they were excluded | Your broker confirms officer inclusion or exclusion elections and endorsements as part of the coverage gap analysis before binding. |
| Overtime billed at full value | Your broker reviews the audit worksheet with you to check that the premium portion of overtime was excluded where your state allows it. |
| Cash and off-payroll labor added to your payroll | Your broker reviews the audit worksheet with you and flags off-payroll payments that need documentation as insured subcontract work. |
| Charges for insured subs on your GL audit | Your broker explains the rating basis on your GL declarations, checks that insured subs were rated as insured, and negotiates with the carrier when they were not. |
| Rates fell but the bill still rose | Your broker separates rate changes from exposure and classification changes on the worksheet, then shops 100+ carriers, including admitted and surplus lines carriers, at renewal. |
| Disputing an audit result | Your broker reviews the worksheet with you, helps submit missing certificates and records, and negotiates with the carrier for a revised audit. |
| Risk of an audit noncompliance charge | Your broker helps you gather the records the carrier requested and follows up with the carrier, which helps prevent a missed request from turning into a charge. |
| Wrap-up and OCIP jobs | Your broker reviews how your own policy treats wrap-up work before the job starts, so that payroll can be set aside at audit. |
Aiden Risk charges no fee to work with it, with no platform fee or subscription; it is paid through standard carrier commissions. We place contractor workers' comp and contractor general liability across 100+ carriers, and we are licensed in 16 states, listed on our licenses page. Check a certificate anytime with the COI checker; for your own certificates, a licensed specialist can then issue a corrected one, often the same day.
Key Takeaways
- An audit swaps estimated payroll, sales, or subcontract costs for actual figures and bills or refunds the difference.
- Subs without a valid certificate covering the whole job are usually added to your payroll, and without the sub's payroll records the full subcontract price can count.
- Many GL policies charge for insured subs too, on a total cost basis, and treat them as inadequately insured if limits, dates, or endorsements fall short.
- Overtime, split payroll, and officer exclusions only help if the records and endorsements exist.
- Falling comp rates in Florida, Arizona, and Texas do not offset audit adjustments driven by exposure and classification.
- Aiden Risk solves these problems in one place: AI that monitors your risk year-round, and a licensed broker who acts on every flag, reviews class codes, officer elections and sub requirements, and works the audit worksheet with you.
FAQs
What is a workers' comp premium audit?
It is the carrier's review, after the policy ends, of your actual payroll and operations during the term. The auditor confirms payroll by class code, checks subcontractor certificates and officer status, and recalculates the premium, producing a bill or a refund.
Why did I owe money after my premium audit?
Usually payroll grew past the estimate, subs without valid certificates were added to your payroll, or employees landed in higher-rated class codes. Unrecorded overtime and included officers can add more. The audit worksheet shows which items drove the change.
Why am I charged for insured subcontractors on my GL audit?
Many GL policies charge a lower rate on the total cost of insured subcontracted work, because the general contractor keeps some liability for it. A sub can still be rated as uninsured, at a higher rate, if its certificate is missing, limits are too low, dates do not cover the work, or a required additional insured endorsement is absent.
What records do premium auditors ask for?
Typically payroll records, Form 941 and state unemployment filings, the general ledger and cash disbursements, job cost records, and subcontractor payments. They also want certificates for every sub, overtime breakdowns, and officer details, and usually send a list in advance.
Can I dispute a premium audit?
Yes. Request the audit worksheet, send the carrier missing certificates or records within its deadline, and ask for a revised audit in writing. If the carrier will not change a classification or rule application, NCCI and state insurance departments have dispute processes that vary by state.
What happens if I don't complete my premium audit?
In states that adopted NCCI's audit noncompliance charge, a carrier can charge up to two times your estimated annual premium after two documented attempts to get your records, and may cancel where state law allows. The charge is refunded or credited if you later complete the audit.
Does pay-as-you-go workers' comp prevent audit bills?
It greatly reduces payroll surprises, because premium is billed from actual payroll during the year. A final audit is still required, and it does not fix uninsured subs, missing certificates, or misclassified employees.
Tired of audit bills you never bid into a job? Aiden Risk catches the usual causes before the auditor does: uninsured subs, short certificates, wrong class codes, and stale payroll estimates. Get an online commercial insurance quote at aidenrisk.com, and a licensed broker will review your class codes, officer elections, and subcontractor terms before renewal, while our AI monitors your exposure all year.
