Workers' Comp Audit Subcontractors: 1099s and Certificates

A carrier generally adds what you paid a subcontractor to your payroll unless you can show that the sub carried its own workers' comp policy. Travelers says on its premium audit page that "we may charge a premium for work performed by an independent contractor/subcontractor." BITCO states the mechanism in plain words: with no current certificate, "we will include the payroll of the subcontractor's employees in the audit." Pinnacol, Colorado's state-created insurer, lists proof of coverage for subcontractors among the papers for an office audit.

The reason is who pays when a worker is hurt. BITCO's page says most workers' compensation laws hold you responsible for injuries to the employees of your uninsured subcontractors, so the carrier prices that exposure at audit. The North Carolina Rate Bureau's Basic Manual (Rule 2-H, revision effective 2024-01-01) turns it into arithmetic: a contractor answers for the compensation benefits of its uninsured subcontractors' employees, and for each sub that does not provide evidence of coverage "additional premium must be charged." Your state's manual and your carrier's filed rules govern your own policy.

So the question at audit is one of paper. For each sub paid in the policy period, do you hold a certificate that covers the dates worked, and do your invoices show what part of the price was labor? The tree below sorts a payment using typical carrier rules.

A valid certificate shows a workers' comp policy that was in force on the dates the subcontractor worked for you, issued by the sub's insurer or agent. Travelers defines it as a document that "identifies the existence of a workers compensation and/or general liability policy," and its list of required contractor records asks for certificates "that cover the dates worked."

Carriers add practical tests. Builders Mutual's audit kit says a binder or certificate with TBD or TBA in the policy number field isn't valid, handwritten certificates aren't acceptable, and the name on the certificate should match the name on the check you pay. It asks you to collect the certificate before work starts, at the start of each new project, and quarterly at a minimum. biBerk asks for workers' compensation certificates on ACORD Form 25 for subcontractors and owner-operators. Beacon Mutual's audit deck states that a sub that does not provide documentation "will be included on the audit and a charge made for the amounts paid to each."

Two catches show up in every carrier's guide. One is the date: a certificate that expired in March does not cover an October job. The other is the type of policy: a general liability certificate is not a workers' comp certificate, which is the next section.

No. Liability and workers' comp policies cover different losses, and carriers audit them separately. Builders Mutual's audit kit puts the split in one answer: if a sub has workers' comp coverage, its exposure is excluded from the workers' comp audit; if it has only general liability coverage, its exposure moves to a lower-rated subcontractor class on the general liability audit, because some exposure remains. BITCO says the same about general liability: it makes a smaller premium charge for subs who have a certificate, and includes sub payroll when none is provided.

The table shows the usual outcome from the Builders Mutual kit, BITCO's page and Beacon Mutual's deck (read 2026-10-19); wording differs by carrier.

Keep the workers' comp certificate and the liability certificate as two separate items in your log, each with its own dates and limits. A vendor with a liability policy and a lapsed workers' comp policy looks fine in the folder and costs full price at audit.

In an Oregon final order dated 2025-06-05, a cleaning company lost its challenge to a workers' comp premium audit bill because most of its subcontractors had liability policies but no workers' comp policy of their own. The Oregon Department of Consumer and Business Services issued the order in the company's dispute with its carrier, adopting an administrative law judge's proposed order of 2024-05-17.

The employer argued the 11 were independent contractors. The judge held that the employer had the burden of proving it under Oregon's statute, ORS 670.600, and found it had not shown the subs were customarily engaged in an independently established business. The carrier had told the owner in writing that the subs "will need to provide proof of their own coverage to be excluded on the audit."

This is one dispute under Oregon law and proves little about your state. The pattern is still instructive: liability paper did not move the outcome, and the carrier's letter named proof of each sub's own coverage as the way off the audit. Source: Oregon DCBS final order, agency case INS-WC 24-01-05, read 2026-10-19.

They change it only when the sub has no workers' comp certificate and your invoices show the split. Carriers then count the labor share as payroll, but they set a minimum share of the price and want original invoices, not summaries. The table sets two published rule sets side by side.

Illustrative: a sub with no workers' comp certificate bills $20,000 for a job. The invoice shows $12,000 of materials and $8,000 of labor. Labor is 40% of the price, below the 50% floor, so the carrier counts $10,000 as payroll. If the invoice were one lump sum and the carrier follows the 90% rule, it counts $18,000. The $8,000 gap is payroll before any class rate applies, and a split on the original invoice closes it.

Sources: North Carolina Rate Bureau Basic Manual Rule 2 and the Builders Mutual audit kit, read 2026-10-19.

Your 1099s are a starting list, not the audit list. Carriers ask for them: Travelers names 1099s with the Form 941 and state unemployment wage reports, biBerk asks for the latest completed calendar year, and MEM's audit checklist says Forms 1099 and 1096 can be used for annual policies. What the auditor wants underneath is every payment to a sub inside the policy dates, with the date and amount of each.

Three gaps appear when you build the list from 1099s alone. The IRS instructions say payments made by credit or payment card are reported on Form 1099-K, not Form 1099-NEC. Payments to a corporation, including an LLC taxed as one, are generally not reported on Form 1099-NEC either. And for payments made in 2026 the reporting threshold is $2,000 (see the Form 1099 guide for 2026), so small vendors may never get a form.

The better source is the ledger. Builders Mutual's kit says that with QuickBooks, the 1099 Detail Report gives subcontractor payment information, and without software the check register or stubs work. Travelers asks for the cash disbursements journal, "including subcontractors, casual labor and material costs." Build the sub list from the vendor ledger for the exact policy dates, compare it with the 1099 file, and explain each difference. Contractor payments support covers how vendor records and W-9s are kept through the year.

A carrier can count owner-operator pay as your payroll unless each owner-operator shows its own workers' comp policy for the dates driven. biBerk's audit FAQ asks for certificates for "subcontractors and owner-operators," and Builders Mutual applies a minimum of one-third of the contract price when the sub is a mobile equipment operator with drivers.

The North Carolina Basic Manual spells out the vehicle case in Rule 2-H-3. If the vehicle's owner has not furnished proof of coverage and the driver's payroll can be obtained, that payroll is included as the contracting employer's payroll. If payroll can't be obtained, or the driver is an owner-operator with no set payroll, one-third of the total contract price is included. Where the price leaves out fuel, maintenance or other services you supply, their value is added before taking the one-third.

Illustrative, using that North Carolina wording: a trucking company pays an owner-operator $90,000 under contract and supplies fuel and maintenance worth $12,000 that the price excludes. With no certificate and no payroll record, the base is $90,000 + $12,000 = $102,000, and one-third of it, $34,000, counts as payroll.

Whether a driver is an owner-operator or an employee is a separate legal test that varies by state. Keep the signed lease or contract, each operator's certificate, the settlement statements, and the dates each operator worked for you.

A 2023 lawsuit alleged that a state-created insurer billed roofers for subcontractors who had coverage. The Denver Gazette reported on 2023-10-20, with an update on 2024-08-27, that Gold Star Premium Roofing and its owner sued Pinnacol Assurance in Denver District Court. These are allegations, not findings.

According to the article, the lawsuit alleges Gold Star was charged nearly $90,000 in additional premium for 2020 on about six subcontractors that Pinnacol said were uninsured, when records showed they were covered. Gold Star says it refused to pay and Pinnacol cancelled the policy. The paper reports that Pinnacol calls some of the suit's claims inaccurate and says it can calculate premium only from the records a company provides: "Bad records will inevitably yield bad calculations."

A search on 2026-10-19 found no later ruling or settlement reported, so the status is unknown to us. The narrow lesson holds whoever is right: the carrier works from what you hand over. A certificate that isn't in the file, or that doesn't match the vendor name or dates on your payment list, gets treated as missing.

A certificate log has one row per subcontractor per policy period, with the fields an auditor checks. Each field below comes from a carrier instruction read on 2026-10-19.

Run the log against the vendor ledger every month. A sub paid in October whose certificate expired in August shows up the day you reconcile, while the work can still be paused or the renewal chased. Payroll journals and reconciliations shows how the payroll side is kept, and the guide on payroll and class codes covers employees.

A free certificate-of-insurance log template has most of these columns as a CSV; add a column for each payment date and amount, and one for the issuing agent. Its example row is Illustrative, not client data.

If the sub really held a workers' comp policy on those dates, the paper can usually be obtained now; if the policy had lapsed, no certificate repairs the gap. Travelers says subcontractors can get a copy of their certificate from their insurance agent, and Beacon Mutual wants one showing coverage for the period the work was performed.

Work in this order. Check the sub's policy dates against the dates you paid them. Ask the sub's agent for a certificate that matches the vendor name, policy number and those dates. Read the audit worksheet and bill for the payments that were charged, sub by sub. Then send the carrier the certificates with the invoices that split labor from materials, inside its dispute window. Windows are short and differ: Beacon Mutual's deck gives the policyholder 30 days to dispute the results in its Premium Adjustment report, with a signed written dispute and support, and says to pay any additional premium you don't dispute meanwhile. Builders Mutual's kit says you have 15 days from the date of the Final Audit Billing to resolve your audit.

Filing the dispute is yours or your representative's to do. A bookkeeper can assemble the schedule of subs, certificates, dates and invoices so the packet is ready to send.

A general liability carrier prices the chance that you answer for harm a sub causes someone else, so contractors who use subs can be audited on what they paid those subs. BITCO's page says you are generally responsible for injuries or damages to third parties caused by your uninsured subcontractors, that its audit includes the payroll of subs without a current certificate, and that it makes a smaller premium charge for subs who have one. Builders Mutual uses the total paid to a sub with a certificate, materials included, and applies its workers' comp rules to subs without one.

The limit a sub's certificate must show differs by carrier.

Sources: Harford Mutual premium audit FAQ, Amerisure premium audit fact sheet and the Builders Mutual audit kit, read 2026-10-19. BITCO also includes the payroll of any sub whose limits fall below its definition of adequate limits.

We organize payroll records, track subcontractor certificates and can attend your premium audit with you where your carrier allows it. We do not sell or advise on insurance coverage. Your carrier assigns class codes.

In practice that means building the subcontractor list from your books for the exact policy dates, keeping the certificate log current month by month, filing the original invoices that split labor from materials, and tying the 1099 file to the vendor ledger so every difference has an explanation. If your carrier asks for a schedule, we prepare it from your records for your review. The auditor decides what counts as payroll and which class applies. Whether a sub is an independent contractor or an employee under your state's law is a legal question for you and your counsel.

If your books need work first, monthly bookkeeping is where it starts. For the employee side of the same audit, see the guide on what counts as payroll and how class codes split it.