PAY-AS-YOU-GO · PREMIUM BILLING GUIDE

Pay-As-You-Go Workers Comp: How Payroll-Driven Premium Billing Actually Works

A roofing contractor running $900,000 of payroll at $14.22/100 carries roughly $128,000 of base premium before the mod — and under traditional billing, a big slice of that is due before the first shingle goes on. Pay-as-you-go replaces the estimate-deposit-audit cycle with premium calculated from each actual payroll run. Here’s the full picture.

Reviewed by Bollinsure Insurance Services — CA Licensed Broker, License #0D94699
Premium billed per payroll run, not per estimate
Updated June 2026

What Pay-As-You-Go Workers Comp Is

Pay-as-you-go is a billing method, not a different insurance product. The policy itself — coverage, class codes, rates, your experience modification — is identical to a traditionally billed workers comp policy. What changes is when and how the premium is calculated and collected. Instead of the carrier estimating your annual payroll up front, collecting a deposit plus installments, and then reconciling everything at a year-end premium audit, a pay-as-you-go carrier calculates premium from your actual payroll each time you run it.

Every pay period, your reported payroll is split by class code, multiplied by the applicable rate per $100 of payroll, adjusted for your mod, and drafted — typically alongside your payroll taxes. A restaurant on class code 9079 at $3.42/100 that runs $40,000 of payroll in a two-week period pays premium on that $40,000, that cycle. Run $22,000 the next cycle because January is slow, and the premium drops with it. The rate never changes mid-term; the payroll it applies to finally matches reality.

Traditional Billing vs Pay-As-You-Go

The traditional model asks you to predict twelve months of payroll before the year starts. The carrier prices the policy on that estimate, collects a deposit and installments against it, and then audits your actual payroll after expiration. If you guessed low, you owe an audit bill — often arriving as a lump sum weeks after you thought the policy year was closed. If you guessed high, you overpaid all year and wait on a return premium check. Either way, your cash and the carrier’s books are out of sync for up to eighteen months.

Feature Traditional (estimate + audit) Pay-as-you-go
Premium basis Estimated annual payroll, set at binding Actual payroll, each payroll run
Up-front deposit Substantial share of estimated annual premium due at inception Little to none — often first payroll cycle only
Mid-year payroll swings Premium unchanged until endorsement or audit Premium tracks the swing automatically
Year-end audit Reconciles estimate vs actual; can produce large additional premium Still occurs, but verifies data already reported — small true-ups
Administrative work Annual estimate, audit prep, disputing audit results Accurate payroll reporting every cycle

Note the fourth row carefully: pay-as-you-go does not eliminate the audit. Carriers still verify class code assignments, subcontractor certificates, and overtime treatment at year end. What it eliminates is the estimate-versus-actual gap that produces the painful audit balances, because the payroll figures the auditor checks are the ones you already paid on.

How Payroll Reporting Drives the Premium

Mechanically, each billing cycle works like a miniature audit. You (or your payroll provider) report gross payroll by employee and class code for the period. The carrier’s billing platform applies the rate for each code — say carpentry, class 5403, at $8.14/100 for field crews and clerical, class 8810, at $0.15/100 for the office — applies your experience modification and any schedule credits, and drafts the resulting premium. Overtime premium pay, excluded remuneration, and officer payroll treatment are handled the same way they would be at audit; the difference is they are handled fifty-two or twenty-six times a year in small pieces instead of once in a lump.

Accuracy of the class-code split still matters enormously. If your carpenters and your estimator are all reported under 5403, you are overpaying every single cycle — the same misclassification problem covered in our class code directory, just surfaced faster. The upside is that a correction made mid-year takes effect on the next payroll run rather than sitting misreported until audit.

Cash-Flow Benefits for Seasonal and Variable Payroll

The core financial advantage is timing. Under traditional billing, a seasonal employer finances the carrier: premium installments are level while payroll is not. Under pay-as-you-go, premium expense lands in the same weeks the payroll expense does, which means it lands in the same weeks the revenue that funds both usually does.

Consider a landscape contractor on class 6217 at $7.62/100 whose crews run heavy from March through October and skeleton through winter. Traditionally billed, that contractor pays roughly level installments through the slow months on payroll that is not being run — and then, if the busy season came in hotter than the estimate, gets an audit bill the following spring on top of it. On pay-as-you-go, December premium reflects December payroll. For businesses where payroll can swing 40–60% between peak and trough, that alignment routinely frees five figures of working capital during the off-season.

Reduced Audit Surprises — Not Zero Audits

The year-end audit balance is where traditional billing hurts most. An employer who estimated $600,000 of payroll and ran $850,000 owes additional premium on $250,000 of payroll at their full rates — at restaurant rates around $3.42/100 that is manageable; at roofing rates of $14.22/100 it is a genuinely dangerous invoice, due in full, after the money from that busy season has already been spent. Our audit guide covers disputing bad audits, but the better strategy is a billing structure where the gap never accumulates.

On pay-as-you-go, the audit still happens and can still move numbers — a misassigned class code, uninsured subcontractor payments picked up as payroll, or mishandled overtime can all generate a true-up. But because the payroll base was reported and paid as it occurred, the reconciliation is against data the carrier already has. In our experience the typical pay-as-you-go audit adjustment is a rounding item, not a crisis.

How Payroll Provider Integration Works

Most pay-as-you-go programs are built around a data connection between your payroll system and the carrier’s billing platform. There are three common arrangements:

Two practical notes. First, employee-to-class-code mapping lives in the payroll system, so it must be set up correctly once and maintained as roles change — a promoted foreman who moves to full-time supervision under class 8601 at $2.42/100 should be remapped, not left at the field rate. Second, if you change payroll providers mid-term, the integration breaks and must be rebuilt; coordinate that switch with your broker before the first missed reporting cycle, because carriers treat non-reporting as grounds to bill on estimates or move toward cancellation.

Who Pay-As-You-Go Fits

The structure earns its keep wherever payroll is hard to predict twelve months out:

It fits less well for employers with genuinely flat, predictable payroll and strong cash reserves — a stable professional office on clerical rates gains little, since the estimate was never going to miss by much. It also assumes payroll discipline: if your payroll runs late or your class-code mapping is chronically wrong, per-cycle billing amplifies the mess instead of hiding it until audit.

How to Get the Most Out of Pay-As-You-Go

  1. Confirm carrier availability for your class codes. Not every carrier offers pay-as-you-go, and some restrict it by class or premium size. An independent broker can tell you which of the markets quoting your risk will bill this way.
  2. Get the class-code mapping right at setup. Every employee in the payroll system must carry the correct code before the first reporting cycle. Verify against the class code directory and your policy’s classifications, and split clerical staff onto 8810 where they qualify.
  3. Use a native payroll integration where one exists. Automatic transmission removes the missed-report risk that self-reporting carries. Ask your payroll provider which carriers they connect to before you pick a market.
  4. Keep subcontractor certificates current anyway. Pay-as-you-go tracks your W-2 payroll; uninsured sub payments still get picked up at the year-end audit exactly as they would on a traditional policy.
  5. Update mappings when roles change. Promotions, department moves, and new divisions all change the code an employee should be reported under. Review the mapping quarterly, not annually.
  6. Watch the mod, not just the billing. Pay-as-you-go fixes cash flow; it does nothing for your experience modification, which still multiplies every cycle’s premium. Claims management and the billing method are separate levers — pull both.
  7. Re-shop the market at renewal regardless. The convenience of an integrated billing setup makes employers sticky, and carriers know it. The right structure at the wrong rate is still the wrong policy; compare against the broader market using our cost guide as a baseline.

The Bottom Line

Pay-as-you-go moves workers comp premium from a guess you finance to an expense you incur — billed when payroll is billed, scaled how payroll scales, and largely pre-reconciled before the auditor ever calls. For seasonal, growing, and staffing-heavy California employers, that usually means no inception deposit, no off-season installments on phantom payroll, and a year-end audit that confirms rather than shocks. It does not change your rates, your classifications, or your mod — those still get won or lost the usual way. Run your numbers through our premium calculator, then have the billing structure and the market both reviewed at once.

Sources & References

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Aaron Bollinger · Bollinsure Insurance Services · CA License #4345268