If you regularly work with contractors, vendors, or third‑party service providers, you’ve probably come across the terms Certificate of Insurance (COI) and endorsement. While they may sound similar, they serve very different purposes—and understanding those differences is key to protecting your business from unnecessary risk.

Here’s a question to consider: Do you know if a COI is enough, or should you be requesting an endorsement instead? This blog breaks down the distinctions between COIs and endorsements, why both matter, and what steps employers can take to stay protected.

What Is a Certificate of Insurance (COI)?

A Certificate of Insurance is a summary document that verifies a business or individual has active insurance coverage. It’s issued by the insurer and provides an at‑a‑glance view of important policy information.

Typical COI details include:

• Policyholder’s name
• Coverage types (general liability, workers’ compensation, auto, etc.)
• Policy limits and effective dates
• Insurer’s contact information

Why it matters: Requesting a COI before hiring a third party helps ensure they carry the necessary coverage, reducing the chance your business is left exposed to liability.

What Is an Endorsement?

An endorsement—also known as a rider—is an official modification to an insurance policy. It changes the policy’s terms by adding, removing, or altering coverage.

Common endorsements include:

• Increasing policy limits
• Adding an additional insured (such as listing your business on a contractor’s policy)
• Expanding coverage to include new risks

Why it matters: Endorsements ensure the actual policy matches your needs, especially when you require protection beyond the standard coverage.

Key Differences Between COIs and Endorsements

• A COI serves as proof of existing insurance—it does not change policy terms.
• An endorsement legally modifies the policy and can broaden or limit coverage.

Best Practices for Employers

To ensure you’re properly protected when working with outside vendors or contractors, keep these steps in mind:

• Always request a COI before starting any engagement.
• Review the COI closely, paying attention to policy limits and expiration dates.
• If you need additional protection, request an endorsement to make sure the policy aligns with your requirements.

Understanding the difference between COIs and endorsements helps you make informed decisions when entering business relationships. A COI confirms that coverage exists, but an endorsement ensures that coverage meets your specific needs.

Before hiring third parties, take time to review your insurance requirements and speak with a qualified insurance professional to ensure you’re fully protected.