Class codes are the foundation of commercial insurance rating for general liability and workers compensation. Every type of business operation is assigned a class code that reflects its risk profile — and that code determines the base rate per $100 of payroll or revenue. Getting class codes right is one of the most important accuracy tasks in commercial submissions.
Workers compensation class codes are assigned by rating bureaus — NCCI in most states, or state-specific bureaus in independent states like California, New York, and Texas. Each code represents a specific job function and carries a base rate per $100 of payroll.
A carpenter (NCCI code 5403) might carry a base rate of $8.00 per $100 of payroll. A clerical worker (code 8810) might carry a rate of $0.20 per $100. The same employer can have multiple class codes — different employees doing different jobs are coded separately.
Misclassifying employees — even accidentally — is one of the most common WC errors. Putting field workers under a clerical code undercharges premium and creates a large audit liability.
Commercial general liability uses a different classification system, typically ISO (Insurance Services Office) or carrier-specific codes. GL codes are based on the type of business or operation rather than individual job functions.
GL is usually rated on one of three exposure bases: • Payroll — common for contracting and service operations • Gross receipts/revenue — common for retail and service businesses • Area (square footage) — common for premises-based risks
The class code determines both the rate and the exposure base. Agents must know which exposure base applies to correctly collect the rating information.
For workers comp: NCCI publishes a Scopes Manual that describes the operations included in each class code. When in doubt, agents can contact their WC markets and ask an underwriter to help classify an unusual operation.
For GL: ISO publishes a Commercial Lines Manual. Many agents use their agency management system or carrier raters, which suggest codes based on business type.
For specialty or hard-to-classify operations, agents should describe the business clearly to the underwriter and ask for the assigned code rather than guessing — misclassification discovered at audit results in additional premium and potential E&O exposure.
If a class code is too low (the operation is riskier than the code suggests):
• For WC: the audit will reassign payroll to the correct higher-rated code, resulting in a large additional premium bill • For GL: the policy may have a rating discrepancy discovered at renewal or audit
If a class code is too high (the insured is being overcharged):
• The client is paying more than necessary • Competitors using the correct code can undercut the premium at renewal
Either way, correct classification matters — both for the client and for the agent's credibility.
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