What Is an Additional Insured Endorsement? Everything You Need to Know
What Is an Additional Insured Endorsement? Everything You Need to Know
When a vendor's employee is injured at your property, or a subcontractor's work causes damage to a tenant's unit, the question of who pays comes down to one document: the additional insured endorsement. If your organization is properly listed as an additional insured on the vendor's policy, you have direct rights under that policy when a covered claim arises. Without it, you are on your own.
This guide explains what an additional insured endorsement is, why it matters, the critical forms property managers should know, how to verify them, and the common mistakes that create gaps even when organizations think they are protected.
What Is an Additional Insured?
An additional insured is a party -- other than the named insured who purchased the policy -- that has been given coverage rights under a commercial insurance policy through an endorsement.
The named insured is the business or individual who bought the policy (your vendor). An additional insured is your organization, added to the vendor's policy by endorsement so that you can access coverage if a claim arises from the vendor's work.
This distinction matters enormously. Simply being named in the certificate holder box on a COI does not make you an additional insured. The certificate holder designation means you received the certificate -- that is all. Only the endorsement to the underlying policy gives you actual coverage rights.
Why Additional Insured Status Matters
Without additional insured status, your exposure to vendor-related claims looks like this:
A vendor's employee is injured on your property. Your organization gets sued. Your own general liability policy responds to the defense and any settlement. Your loss history is affected. Your premiums may increase.
An HVAC subcontractor causes water damage during a repair. You file a claim against the vendor's policy as a third party. Without additional insured status, the carrier has no contractual obligation to defend you or cover your losses from the vendor's work. You can still sue the vendor, but that is a separate legal proceeding -- slower and less certain than a direct insurance claim.
A landscaping crew damages a tenant vehicle. As an additional insured, you can tender the claim directly to the vendor's liability carrier. Without the endorsement, you bear the tenant relations cost and litigation risk yourself.
For property management companies managing 200 to 2,000 units with dozens or hundreds of active vendor relationships, the aggregate exposure from missing additional insured endorsements can reach millions of dollars annually.
The Two Essential Endorsement Forms
The Insurance Services Office (ISO) publishes standardized endorsement forms that are incorporated into commercial general liability policies. Two forms are critical for property managers:
CG 20 10 -- Additional Insured: Owners, Lessees, or Contractors (Ongoing Operations)
CG 20 10 extends additional insured coverage for bodily injury and property damage liability arising out of the named insured's ongoing operations performed on behalf of the additional insured. This covers you while the vendor is actively performing work.
Key point: CG 20 10 is for ongoing operations only. It does not extend coverage to claims that arise after the work is complete.
CG 20 37 -- Additional Insured: Owners, Lessees, or Contractors (Completed Operations)
CG 20 37 extends additional insured coverage for claims arising out of the named insured's completed work. This is the form that protects you after the vendor finishes the job.
Why this matters: Many construction-related claims surface months or years after work is completed. A roof installation that appeared fine at completion may develop leaks in the next season. Electrical work that passed inspection may later contribute to a fire. Without CG 20 37, your additional insured status does not cover these completed operations claims -- even if you required and received CG 20 10.
Best practice for any vendor performing physical work on your properties: Require both CG 20 10 and CG 20 37. Specify both form numbers in your vendor contracts and in your COI request.
CG 20 26 -- Additional Insured: Designated Person or Organization
CG 20 26 names you specifically as an additional insured by legal entity name. Some insurers use this form instead of or in addition to the project-specific forms above. Confirm with the vendor's broker which form is being used and whether it meets your contract requirements.
Blanket Additional Insured Endorsements
Some policies include a blanket additional insured endorsement that automatically extends additional insured status to any party the named insured is required by written contract to name as additional insured. Blanket endorsements are convenient -- they do not require the carrier to amend the policy for each new vendor relationship. However, confirm with the carrier that:
- The blanket language in the policy actually triggers based on your contract requirement
- Your entity is not excluded from coverage under the blanket endorsement
- The scope of coverage (ongoing, completed, or both) matches your requirements
How to Verify Additional Insured Status
This is where most organizations fall short. Checking the "Additional Insured" checkbox on an ACORD 25 form is not verification. The checkbox represents the broker's assertion that an endorsement exists -- not proof of the endorsement's existence or wording.
Level 1: COI Checkbox and Description of Operations
At minimum, the COI should show the additional insured checkbox marked on the commercial general liability line. The description of operations field should contain language identifying your organization and, ideally, citing the endorsement form number.
Example of acceptable description language: "Additional Insured: XYZ Property Management LLC per CG 20 10 and CG 20 37 with respect to operations performed at [property address]."
This is a reasonable starting point for lower-risk vendors. It is not sufficient for high-risk vendors or when significant exposure is at stake.
Level 2: Endorsement Page Request
For Tier 1 and Tier 2 vendors (per your vendor compliance requirements), request the actual endorsement page from the vendor's broker. The endorsement page will show:
- The exact endorsement form number (CG 20 10, CG 20 37, etc.)
- The named additional insured (your entity's legal name -- verify this matches exactly)
- Any project or location limitations
- The policy number it attaches to
Review the endorsement page against each of these elements. A mismatch between the named additional insured and your contract entity is a deficiency that requires correction.
Level 3: Direct Carrier Confirmation
For high-value contracts or situations where you have reason to doubt a certificate's accuracy, call the insurance carrier directly (using the carrier's main number from their public website, not a number from the certificate) and ask a carrier representative to confirm:
- The policy identified on the COI is active
- Your entity is listed as an additional insured
- The endorsement form(s) match what was represented on the certificate
Document the date, time, carrier representative name, and confirmation details.
Common Mistakes That Invalidate Additional Insured Coverage
Wrong Entity Name
The most common deficiency. Your management company is named "ABC Property Management LLC" but the endorsement names "ABC Management" or "ABC Properties." These are different legal entities. If a claim arises, the carrier can deny additional insured coverage on the basis that you are not the named entity.
Every COI request should provide the exact legal names of all entities that require additional insured status. Do not assume the vendor or their broker knows your correct legal name.
Missing CG 20 37
Accepting CG 20 10 without also requiring CG 20 37 for construction and renovation vendors is one of the most consequential gaps in property management COI programs. Construction defect claims are frequently filed years after completion -- often after the vendor's policy has renewed multiple times. Without CG 20 37, completed operations claims fall through the coverage gap.
Endorsements That Reference Project Addresses Only
Some endorsements are written to apply only at a specific project address or location. If your vendor performs work across multiple properties in your portfolio, verify that the endorsement covers all locations where they work -- not just the address where they first performed work.
Accepting Certificates Without Endorsement Documentation
Especially for high-risk vendors: the COI checkbox is the starting point, not the finish line. Request the endorsement page. This one step catches the majority of additional insured deficiencies before they become claim-time problems.
Not Updating Endorsements When Legal Entities Change
If your organization restructures, acquires new entities, or changes legal names, your additional insured status on existing vendor policies may reference outdated entity names. Audit your vendor files whenever your organizational structure changes to ensure endorsement entity names remain current.
Additional Insured vs. Certificate Holder
These two designations are frequently confused:
Certificate holder: The party to whom the COI was issued. Being a certificate holder means you received the document. It confers no coverage rights. In some policy forms, certificate holders receive cancellation notice if the policy is cancelled, but this is not guaranteed and "endeavor to" language in certificates makes it unreliable.
Additional insured: A party with actual coverage rights under the policy, added by endorsement. This is what protects you when a claim arises from a vendor's operations.
You should be both the certificate holder and an additional insured. Most certificate requests ask for both designations, but confirm that both are addressed when you review the submitted COI.
Key Takeaways
- Additional insured status is conferred by endorsement to the underlying policy -- not by a COI checkbox.
- CG 20 10 covers ongoing operations; CG 20 37 covers completed operations. Require both for construction and renovation vendors.
- Verify the endorsement entity name matches your exact legal name.
- Request endorsement pages from high-risk vendors, not just the COI.
- Certificate holder status is not the same as additional insured status.
Frequently Asked Questions
What is the difference between a named insured and an additional insured?
The named insured is the business or individual who purchased the insurance policy. An additional insured is a separate party added to the policy by endorsement. The named insured has full coverage rights under the policy. An additional insured has coverage rights only to the extent covered by the endorsement, which is typically limited to claims arising from the named insured's operations.
Can I be an additional insured on multiple policies at the same time?
Yes. You can be an additional insured on every vendor's general liability policy simultaneously. This is the standard expectation in property management -- your organization is listed as an additional insured on dozens or hundreds of vendor policies at any given time.
Does additional insured status extend to umbrella policies?
Not automatically. If you require additional insured status on a vendor's umbrella policy, you must specify this in your contract and confirm the endorsement covers the umbrella separately. Many standard COI requests miss this, leaving a gap in coverage for high-severity claims that exceed primary limits.
What should I do if a vendor refuses to add me as an additional insured?
A legitimate vendor who meets your contract requirements should have no issue adding you as an additional insured. Refusal typically indicates that the vendor's policy excludes this type of endorsement (rare), that the vendor is attempting to avoid the administrative step, or that the vendor does not carry adequate coverage. Do not authorize site access until additional insured status is confirmed.
Do I need to require CG 20 37 from every vendor?
CG 20 37 is most important for vendors who perform physical work that could produce latent claims -- construction, renovation, roofing, plumbing, electrical, HVAC. For service vendors whose work does not create the same type of completed operations exposure (landscaping maintenance, janitorial), CG 20 10 alone may be adequate depending on your risk advisor's guidance.
Additional insured verification is one of the highest-impact compliance activities for property managers. COIPulse tracks endorsement status, flags entity name mismatches, and alerts you when endorsements are absent or inadequate -- automatically, across your entire vendor portfolio. Start free or grade your endorsement compliance now. Also see our complete guide to COI tracking for property managers.