What is combined single limit (CSL) in commercial auto insurance?

Complete Guide to Combined Single Limit (CSL) in Commercial Auto Insurance

Why This Question Matters for Colorado and Utah Residents

Choosing the right liability coverage directly protects your business's assets and future. CSL is a unique option in commercial auto insurance that addresses specific regional risks, such as severe weather events and high-value liability claims, especially relevant for business owners operating in Colorado and Utah.

• Major liability risks: Colorado's I-25 corridor and Utah's I-15 see frequent high-dollar collisions—recent claims in Northern Colorado average $42,100, while multi-vehicle incidents can exceed $500,000 in liability.
• Hail & weather: With 42% of comprehensive claims in Colorado due to hail and $3 billion in insured statewide weather losses per decade, businesses need flexible coverage that adapts to sudden, costly events.
• Legal standards: Both states require minimum commercial liability, but CSL can offer broader protection and help fulfill client or contract requirements for higher, easier-to-manage limits.

What Most People Get Wrong

Many business owners believe minimum split limits are enough, not realizing a single crash—or hailstorm—can exhaust those protections, leaving significant liability uncovered. Others assume property damage and bodily injury can never overlap, which is frequently untrue in major incidents.

Another misconception: CSL costs dramatically more than split limits. In Colorado and Utah, the premium difference is typically only 20–30%, but your protection may double, especially in high-exposure claims.

The Complete Picture

Combined Single Limit (CSL) in commercial auto insurance sets a single dollar limit (e.g., $1 million) that can be used for any combination of bodily injury and property damage claims from a single accident. This is different from "split limits," which separate payouts into distinct buckets (e.g., $50,000 for injury per person, $100,000 per accident, $25,000 for property damage).

With CSL, if a severe crash causes both injuries and property losses, you don't have to worry about either component being underfunded—your entire coverage pool can go toward whichever need is greatest. This flexibility is especially important in business situations with multiple vehicles, valuable equipment, or passenger vans, and in regions (like Colorado and Utah) with high auto claim severity. Most growing companies, contractors, and transit businesses along I-25 and I-15 now select $1 million CSL for true risk protection.

Making the Right Decision for Colorado and Utah Residents

Question 1: What’s the largest claim my business could realistically face?

In both states, serious collisions can exceed $500,000 in total liability (especially with commercial vehicles). Think about worst-case scenarios—multi-vehicle collisions on I-25, hail damage during peak storms, or injuries to multiple people in one event.

• Does your business operate in high-traffic or high-risk zones (Denver, Salt Lake City, Fort Collins)?
• Would a $1M CSL cover more real-life situations than split limits, or would split options leave a gap?

Question 2: Will a CSL make claims and compliance easier?

CSL means a single, unified limit for each accident, making claims—and certificate of insurance management—simpler. For example, contract work for construction in Boulder often requires $1M CSL for ease of compliance, not just protection.

Question 3: Is the cost of higher limits justified by my risk?

With business auto premiums in Colorado and Utah averaging $1,800/year, increasing to a $1 million CSL usually only raises premiums by 20–40%, but it can save your business from catastrophic out-of-pocket costs. Consider the value of asset protection, business continuity, and client confidence when weighing modest premium increases versus potential uncovered losses.