Combined Single Limit (CSL)
A single liability limit that applies to bodily injury and property damage combined, most commonly used on commercial auto policies.
What It Is
Combined Single Limit, abbreviated CSL, is a single liability limit that applies in aggregate to both bodily injury and property damage arising out of any one accident. For example, a $1,000,000 CSL on a Business Auto policy will pay up to $1 million total per accident, allocated however the claim demands between bodily injury and property damage.
CSL contrasts with split limits, where bodily injury per person, bodily injury per accident, and property damage are each capped separately (commonly written as 100/300/100 or similar). On the same accident, split limits can leave gaps: a $500,000 bodily injury claim against a 100/300/100 policy is capped at $100,000 per person, while a $500,000 CSL would respond fully up to the limit.
CSL is the preferred structure on most commercial auto schedules because it provides a flexible pool of limit, simplifies claim handling, and aligns with umbrella attachment points. Many state minimum financial responsibility laws still permit split limits, so brokers must verify that each insured carries a CSL high enough to satisfy contractual and underwriting requirements.
Why It Matters for Brokers
An insured who believes they have a $1 million policy but actually carries 100/300/100 split limits faces a brutal surprise after a serious accident. Contractual requirements such as $1 million CSL on a lease or service agreement are not satisfied by 100/300/100, and certificate holders frequently reject split limit COIs. Brokers who let split limits slide through on commercial auto risk both contract breach claims from the insured's customers and E&O claims from the insured. Defaulting to CSL and explaining the difference at every policy review is core to the standard of care.
Real-World Example
A delivery contractor with a 250/500/100 split limit auto policy is in a multi vehicle accident producing $380,000 of bodily injury to one occupant and $140,000 of property damage to two vehicles. The split limit caps the bodily injury at $250,000 per person and pays the $100,000 property damage limit, leaving $170,000 uncovered. A $1 million CSL would have paid the entire $520,000 from the single limit. The agency rewrites the account at renewal on a $1 million CSL with $5 million umbrella attachment.
Common Mistakes
- 1Quoting split limits to match a state minimum without confirming that contractual requirements demand a Combined Single Limit at $1 million or more.
- 2Issuing a COI showing $1,000,000 limits when the underlying policy is actually 250/500/100, which becomes a fraudulent certificate exposure for the agency.
- 3Failing to verify that the umbrella attaches above the CSL rather than above split limits, creating a coverage gap that emerges only at the time of a serious loss.
- 4Allowing the insured to step down from CSL to split limits at renewal for premium savings without documenting the rejection in writing.
How brokerageaudit.com Handles This
Policy Checker compares quoted and bound auto limits against contract requirements and certificate holder expectations, flagging any split limit policy where a CSL is required. COI Tracker prevents issuance of a $1,000,000 limit certificate when the bound policy is structured on split limits.