Payroll Splitting Between Class Codes: The Records Requirement

Plenty of small businesses have employees who genuinely do more than one kind of ratable work — a carpenter who frames one week and installs trim the next, a cabinet-shop employee who also does field installation. In principle, that person's payroll can be split between the two corresponding class codes, each at its own rate. In practice, almost none of that flexibility is available unless you have the records to back it up.

The rule

Where an employee performs work that falls under more than one ratable classification, payroll may be split between those classifications only with verifiable payroll records allocating hours or wages to each class. Without those records, the entire payroll for that employee goes into the single highest-rated code that applies to any part of their work. This is sometimes called the interchange-of-labor rule, and it is one of the most common sources of self-inflicted overcharges we see — not because a misclassification happened, but because a legitimate cost-saving split was never available for lack of paperwork.

A concrete example

Consider an employee who splits time between shop fabrication of custom cabinets (code 2812 — Cabinet Manufacturing, Wood, illustratively $3.50–$8 per $100 of payroll) and field installation of trim and cabinets (code 5437 — Carpentry, Cabinet Work or Interior Trim Installation, illustratively $4–$12). Both are legitimate, separately ratable kinds of work, and in some businesses the same employee also frames on a residential job site under code 5645, illustratively $8–$25. With a clean weekly log showing which days were shop work, which were trim installation, and which were framing, the payroll for that employee can be split three ways at three different rates. Without any log, all of it goes into whichever of the three codes carries the highest rate — in this case, likely the framing rate — regardless of how the time actually broke down.

What counts as verifiable

The bar isn't exotic, but it does need to be contemporaneous and specific enough to allocate hours or wages by class:

• Timesheets or job-costing records that tag hours to a specific job or task type.
• Work orders or job tickets that identify which kind of work was performed on a given day.
• Payroll system reports that already break wages down by department or cost code, if that breakdown maps cleanly to your class codes.

What generally doesn't hold up: a verbal estimate that someone spends "about half their time" on one kind of work, or a single note in a personnel file with no dates or hours behind it. The records need to show the actual allocation, not a recollection of it.

Why the highest-rated code, specifically

It's worth understanding why the default falls to the highest applicable rate rather than, say, an average of the codes involved, or the governing classification. The logic is conservative by design: since the actual mix of work is unknown without records, the rating system assumes the worst case for exposure rather than guessing at a blend. That's precisely why the records requirement is worth taking seriously — it isn't a minor administrative box to check, it's the entire difference between a blended rate and the single most expensive one.

Why most businesses lose this option by default

Small businesses generally track time for payroll and scheduling purposes, not for workers' comp classification — there's rarely a business reason to log which task an hour of work went toward unless someone is thinking specifically about class-code allocation. That means the records needed to support a split often just don't exist, even in businesses where the underlying work genuinely spans multiple classifications. The fix isn't complicated, but it does require deciding to track it before the fact, not after.

Setting up the records going forward

You don't need dedicated software. A simple weekly log — employee, date, job or task type, hours — kept consistently is enough to support a split at your next audit, as long as it's maintained in the ordinary course rather than reconstructed right before the auditor arrives. If you already use job costing for profitability tracking, check whether that same data can be repurposed to show the class-code breakdown; often it already captures most of what's needed.

How granular does the split need to be?

Records don't need to track every minute of every day to be useful — daily or weekly granularity is generally sufficient, as long as it's consistent and covers the whole period in question. What matters more than precision is completeness and consistency: a log with occasional gaps is still far more useful than no log at all, but a log that only covers convenient weeks and skips busy ones is easier for an auditor to discount as unrepresentative of the full picture.

A word of caution on manufactured records

Records assembled after the fact, right before an audit or a dispute, with no contemporaneous basis, tend to carry far less weight than records that were kept as a matter of routine — and an auditor who suspects a log was reconstructed for the occasion is unlikely to accept it at face value. The goal isn't to produce a document that satisfies a checklist; it's to have genuine, ongoing records that happen to satisfy the requirement because they reflect how the business actually operates.

What about past audits with no records?

If a past audit charged everything at the highest-rated code because no split records existed, a full retroactive fix usually isn't available without records from that period. That said, partial records — even incomplete timesheets, job invoices, or scheduling notes from the period in question — can sometimes still support a partial dispute, so it's worth gathering whatever exists rather than assuming nothing will help. See our guide on how to dispute a workers' comp audit for how to present partial evidence.

Job costing you already have might already be enough

Many businesses that would benefit from a payroll split already collect the raw data for other reasons — job costing for bidding accuracy, time tracking for client billing, or crew-scheduling software that logs which job each person worked each day. Before building a new tracking system from scratch, check whether an existing system already captures enough detail to map onto your class codes. It's common to discover the records essentially already exist; the missing step is just pulling them into a format an auditor can use.

The same discipline applies to subcontractors

This records requirement isn't unique to your own employees — the same logic of "no records means the highest rate applies" shows up in how subcontractor invoices get charged when labor and materials aren't itemized separately. See certificates of insurance and subcontractors for that side of the same underlying principle, and the seven most expensive class code mistakes for how this fits alongside the other recurring overcharges we see.