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Insurance , Workers Comp

Simplifying Certificate of Insurance (COI) and Waiver of Subrogation (WOS): Key Differences and Their Importance

In the world of insurance and risk management, you might come across two important terms: Certificate of Insurance (COI) and Waiver of Subrogation (WOS). While both are essential, they serve different purposes. Let’s break down what each one is, why they matter, and when to use them.

What is a Certificate of Insurance (COI)?

A Certificate of Insurance (COI) is a document from an insurance company that proves you have insurance coverage. It gives a summary of your insurance policy without going into all the details. Third parties, like clients, landlords, or contractors, often ask for a COI to make sure you have the right insurance.

Key Parts of a COI:

Policyholder Information: Name and address of the insured.

Insurance Company Information: Name and contact details of the insurer.

Policy Numbers: Unique IDs for the insurance policies.

Types of Coverage: What the insurance covers (e.g., general liability, workers’ compensation).

Policy Limits: The maximum amount the insurer will pay for each type of coverage.

Effective and Expiration Dates: When the coverage starts and ends.

Description of Operations: What activities or operations are covered by the insurance.

Purpose and Use of a COI:

Proof of Coverage: Shows that you have the required insurance.

Contractual Compliance: Ensures you meet the insurance requirements of a contract.

Risk Management: Helps third parties check that you have enough insurance to cover potential risks.

What is a Waiver of Subrogation (WOS)?

A Waiver of Subrogation (WOS) is a clause in an insurance policy where the insurer gives up the right to seek repayment from a third party responsible for a loss. This means if the insurer pays for a claim, they won’t try to get the money back from the party that caused the damage.

Key Aspects of a WOS:

  • Relinquishment of Recovery Rights: The insurer waives their right to seek recovery from the responsible party. 
  • Policy Amendment: A WOS is added as an endorsement or amendment to an existing policy. 
  • Specific to Relationships: Often used in contracts to protect ongoing business relationships from legal disputes.

Purpose and Use of a WOS:

Facilitates Business Relationships: Prevents insurers from suing each other, helping maintain good relationships.

Contractual Requirements: Many contracts, especially in construction and leasing, require a WOS to avoid litigation. 

Risk Management: Reduces the risk of legal disputes and associated costs.

Key Differences Between a Certificate of Insurance (COI) and a Waiver of SUbrogation (WOS)

Function and Purpose:
COI: Provides proof of insurance coverage and details the policy.
WOS: Waives the insurer’s right to seek recovery from a third party, protecting business relationships.

Document Type:
COI: A standalone document summarizing insurance coverage.
WOS: An endorsement or clause within an insurance policy.

Use Cases:
COI: Used to show proof of insurance to clients, contractors, landlords, or other third parties.
WOS: Included in contracts to prevent insurers from pursuing subrogation claims against third parties.

COI: Detailed information about the types of coverage, policy limits, and effective dates.
WOS: A specific clause that waives subrogation rights, often not detailed in a COI.

When to Use Each

Certificate of Insurance (COI):
– Needed when entering contracts that specify insurance coverage requirements.
– Required to demonstrate compliance with insurance mandates in business relationships.
– Commonly requested by landlords, clients, or contractors.

Waiver of Subrogation (WOS):
– Included in contracts to maintain strong business relationships.
– Used in industries like construction, where subrogation claims could disrupt collaboration.
– Required by contractual agreements to avoid potential legal disputes.


Both a Certificate of Insurance (COI) and a Waiver of Subrogation (WOS) are vital in insurance and risk management, but they serve different purposes. 


A COI provides proof of insurance coverage, while a WOS protects business relationships by waiving the insurer’s right to seek recovery from third parties. 


Knowing the differences between these two can help you navigate your insurance needs effectively and ensure you have the right protections in place.