When renting a car, protecting yourself from third-party liability is just as important as covering damages to the rental vehicle. This is where Supplemental Liability Insurance (SLI) comes in.
In this guide, we’ll break down SLI, what it covers, how it compares to other insurance options, and whether you should include it in your rental agreement.
Supplemental Liability Insurance (SLI) is an optional rental car coverage that protects you against claims from third parties for:
✔ Bodily injury (e.g., medical expenses for pedestrians or other drivers)
✔ Property damage (e.g., damage to another vehicle, fences, buildings)
Most countries require drivers to have minimum liability coverage, but these limits are often low. SLI increases your liability coverage, ensuring you are financially protected in case of an accident.
Important: SLI does not cover damage to the rental car itself (that’s covered by CDW or LDW).
Pro Tip: Always read the fine print, as SLI coverage varies by rental company and country.
| Coverage Type | Covers Damage to Rental Car? | Covers Third-Party Injuries? | Covers Third-Party Property Damage? | Covers Personal Injuries? |
|---|---|---|---|---|
| Supplemental Liability Insurance (SLI) | ❌ No | ✅ Yes | ✅ Yes | ❌ No |
| Collision Damage Waiver (CDW) | ✅ Yes | ❌ No | ❌ No | ❌ No |
| Loss Damage Waiver (LDW) | ✅ Yes | ❌ No | ❌ No | ❌ No |
| Personal Accident Insurance (PAI) | ❌ No | ❌ No | ❌ No | ✅ Yes |
| Theft Protection (TP) | ❌ No | ❌ No | ❌ No | ❌ No |
Takeaway: SLI is essential for covering damages to other people and property. If you want full protection, combine SLI, CDW, and PAI.
The price of Supplemental Liability Insurance varies based on:
| Car Type | Location | Daily SLI Cost |
|---|---|---|
| Economy Car | USA | $10 – $25 |
| SUV | Europe | $15 – $35 |
| Luxury Car | Mexico | $15 – $40 |
Tip: Some credit cards do not cover third-party liability, so check before declining SLI.
Tip: Always compare rental company vs. third-party insurance before booking.
✔ Renting a car in the USA, where lawsuits are common.
✔ Your credit card doesn’t cover third-party liability.
✔ You don’t have personal auto insurance that extends to rentals.
✔ You want higher liability limits beyond the rental company’s minimum coverage.
❌ Your rental already includes high liability coverage.
❌ Your personal auto insurance covers third-party liability (mostly in the U.S.).
❌ You’re renting in a low-risk area (e.g., small rural towns).
Pro Tip: Even if you have liability coverage, double-check the coverage limits—many rental companies only provide the bare minimum.
Supplemental Liability Insurance (SLI) is a must-have for high-risk locations, especially in countries like the USA, where lawsuit settlements can be expensive. While it adds to your rental cost, it prevents you from paying out-of-pocket for third-party damages.
Before deciding, review your personal insurance, credit card benefits, and rental agreement to see if SLI is already included or worth adding.
No, SLI only covers third-party liability. For rental car damage, you need CDW or LDW.
No, but many countries require basic liability insurance, which may not be enough. SLI raises your coverage limits.
Yes, third-party insurers like RentalCover.com and Allianz offer SLI at lower prices than rental companies.
Most credit cards do not cover liability insurance—always check before declining SLI.
Yes, but make sure your personal auto insurance covers liability in rental cars, especially internationally.
