Additional Insured Endorsements: Why Clients and Landlords Request Them
Key Takeaways
- An additional insured gets liability protection from your policy, but only for claims arising from your work or operations.
- Landlords and clients request this status to protect themselves from lawsuits connected to your business activities.
- Being listed as an additional insured does not give someone the same rights as the named insured — they can't cancel the policy or file certain types of claims.
- The endorsement must be explicitly added by the insurer; a certificate of insurance alone does not create additional insured status.
- Coverage scope depends heavily on the specific endorsement form attached — always verify which ISO forms are included.
- Failing to provide additional insured status when contractually required can trigger a breach of contract, even if a claim never occurs.
Additional Insured Endorsement
An additional insured endorsement is a modification added to an existing insurance policy that extends certain liability protections to a third party — typically a client, landlord, or property owner. The third party doesn't own the policy, but they gain coverage under it for specific claims tied to the policyholder's operations or activities. This is a contractual requirement in many business and commercial lease relationships.
Coverage scope varies significantly by endorsement form. ISO form CG 20 10 covers ongoing operations; CG 20 37 covers completed operations. Many contracts require both, and courts have interpreted coverage differently based on which forms were attached.
What's Actually Happening When You Add Someone as an Additional Insured
When a client sends you a contract with a requirement that you add them as an additional insured, a lot of business owners just forward it to their broker and hope for the best. That works fine — until it doesn't. Understanding what you're agreeing to, and what the endorsement actually does, can prevent expensive surprises on both sides of the relationship.
Here's the short version: adding someone as an additional insured extends your general liability (GL) policy to cover them for certain claims that arise out of your work. They're not getting their own policy. They're stepping into a limited position of protection under yours — but only for liability that connects back to your operations.
Think about a contractor hired to renovate an office building. The property owner requires the contractor to add them as an additional insured. If a visitor trips over the contractor's equipment and sues both the contractor and the building owner, the building owner can tap into the contractor's GL policy for their own legal defense and any resulting damages. Without that endorsement, the building owner would be fighting that lawsuit on their own dime.
The mechanism is straightforward, but the details — which ISO form, what scope of operations, whether completed work is included — matter enormously when an actual claim surfaces. That's where most people get burned.
Why Clients and Landlords Request This Status
The motivations are purely defensive, and they're rational ones. When you hire a contractor, bring in a vendor, or lease space to a business, you're inviting someone else's risk into your orbit. Additional insured status is how the party with the most property or reputational exposure shifts some of that risk back to the party whose operations created it.
Clients Who Hire Vendors or Contractors
A property management company hires a landscaping firm. One of the landscaping crew's machines flings a rock through a tenant's window, injuring the tenant. The tenant sues the property management company because they hired the landscaper. Without additional insured status on the landscaper's GL policy, the property management company is funding their own defense and any settlement out of their own liability policy — or worse, out of pocket.
With proper additional insured coverage, they can tender that defense to the landscaper's insurer. That's why clients in construction, property management, events, and professional services require this status almost universally.
Landlords Leasing Commercial Space
Commercial landlords face constant exposure from tenants' business activities on their premises. A customer slips in a retail tenant's store and decides to sue the building owner as well as the tenant. The landlord's own policy would respond — but they'd much rather the tenant's policy pick up the tab for what is fundamentally the tenant's operational risk.
Most commercial lease agreements have explicit additional insured language. If you're a business owner signing a commercial lease, expect to see it. For a deeper look at how coverage responsibilities split between landlords and tenants in leased space, see tenant improvements and betterments coverage.
85%+
Commercial leases requiring additional insured status
Industry surveys consistently show the vast majority of commercial lease agreements include mandatory additional insured requirements for tenants.
CG 20 10 & CG 20 37
ISO forms most frequently required together
Construction industry contracts increasingly mandate both ongoing and completed operations forms to close the coverage gap between active work and post-completion claims.
$0
Cost to the additional insured party
The additional insured pays nothing to be added to someone else's policy — the endorsement cost, typically modest, falls on the named insured's premium.
Primary & Noncontributory
Contract language required beyond basic AI status
A growing share of commercial contracts now require explicit primary and noncontributory endorsement language, not just additional insured designation alone.
General Contractors Managing Subcontractors
General contractors are exposed to the work of every subcontractor on a jobsite. If a sub causes property damage or injury, the GC often ends up named in the lawsuit. Requiring all subs to add the GC as additional insured is standard practice — it's basic risk management, not legal aggression.
State Laws Affect Scope of Coverage
Several states — particularly those with anti-indemnity statutes in construction — restrict how broadly additional insured coverage can extend. In some states, an endorsement cannot cover the additional insured's own negligence, regardless of what the contract says. Always consult with a broker familiar with the laws in your operating state before assuming your endorsement language will hold up.
Blanket vs. Scheduled Endorsements
Some policies automatically extend additional insured status to any party required by written contract (blanket endorsement), while others require each additional insured to be specifically listed (scheduled). Blanket endorsements are more operationally efficient for businesses with many vendor or client relationships, but the underlying contract must actually require the coverage — blanket forms don't apply by default to every business relationship.
Policy Limits Are Shared, Not Multiplied
When an additional insured makes a claim under the named insured's policy, they're drawing from the same per-occurrence and aggregate limits as the named insured. If the named insured has already had a large claim that year, the remaining aggregate may be significantly reduced. This is one reason clients often require minimum policy limits — to ensure adequate coverage remains available.
What Additional Insured Status Does and Doesn't Cover
This is where people consistently misread what they're getting. Additional insured status under a general liability policy is not a blanket shield. It has a defined — and limited — scope.
What It Covers
- Third-party bodily injury: If someone is injured due to the named insured's work and sues the additional insured, the policy responds.
- Third-party property damage: Damage caused by the named insured's operations that results in a claim against the additional insured.
- Legal defense costs: Covered under the policy's duty to defend, which kicks in even before liability is determined.
- Advertising and personal injury: Depending on the form, some coverage for libel, slander, or copyright infringement arising from the named insured's operations.
What It Doesn't Cover
- The additional insured's own negligence: Standard ISO forms limit or exclude coverage for claims arising from the additional insured's sole negligence. Some states restrict how broadly additional insured coverage can extend, particularly in construction.
- Professional errors and omissions: GL doesn't cover professional mistakes — that requires a separate E&O or professional liability policy.
- Employee injuries: Workers' compensation is a separate policy entirely.
- Property owned by the additional insured: GL is third-party liability coverage. First-party property damage requires a commercial property policy.
- Completed operations (unless specifically endorsed): Standard ongoing operations endorsements don't automatically cover claims that arise after the work is finished. This requires ISO form CG 20 37 or equivalent.
Always Request the Actual Endorsement Form
Never accept a certificate of insurance as proof of additional insured status. Ask for a copy of the endorsement form itself — with the ISO form number identified. This is the only document that legally modifies the policy to include you as an additional insured. Filing this with your contract records could save significant time and money if a claim ever arises.
Match the Legal Name Exactly
The name on the additional insured endorsement must match the legal name of the entity requiring coverage. "ABC Properties" and "ABC Properties LLC" are different legal entities. A mismatch can create grounds for an insurer to deny or complicate a claim. Always provide the requesting party's exact legal name and verify it appears correctly on both the endorsement and the certificate.
Track Renewal Dates Proactively
Additional insured endorsements expire when the policy renews unless reattached. Set calendar reminders 60 days before policy renewal to reissue updated certificates and confirm endorsement continuity. Clients and landlords who require ongoing coverage should also be tracking your renewal dates — a lapse puts both parties at risk.
Endorsement Forms: Why the Fine Print Is the Whole Story
When a contract says "add us as additional insured," it sounds simple. But your insurer is going to attach a specific endorsement form, and the differences between forms can be the difference between coverage and a denied claim.
ISO CG 20 10 — Ongoing Operations
This is the most commonly requested form. It covers claims arising from the named insured's ongoing operations — work that's actively in progress. It's the baseline most contracts require, but it doesn't extend to claims that emerge after the job wraps up.
ISO CG 20 37 — Completed Operations
This form covers claims arising from completed work. Construction defects, injuries from a finished product, property damage discovered after a project ends — these fall under completed operations. Many contracts now explicitly require both CG 20 10 and CG 20 37 because the gaps between them have cost parties significant money in contested claims.
Blanket Additional Insured Endorsements
Some policies include a blanket additional insured endorsement, which automatically extends coverage to any party required by written contract to be named as additional insured. This is operationally convenient — you don't need a separate endorsement for every client. But blanket endorsements still have their own limiting language, and the terms of the underlying contract matter for determining the scope of coverage.
Primary and Noncontributory Language
Many contracts don't just require additional insured status — they require the coverage to be primary and noncontributory. This means the named insured's policy responds first, before the additional insured's own policy is triggered. Without this language, insurers may try to share the loss across both policies. If your contract requires it, confirm your endorsement explicitly states primary and noncontributory status.
“The difference between a certificate of insurance and an actual endorsement is the difference between a receipt and the product itself. One proves a transaction happened; the other is the thing you actually need when something goes wrong.”
— Marcus Delgado, Former Commercial Lines Underwriter, Property & Liability Specialist
The Certificate of Insurance Misconception
I'll say this plainly because it comes up constantly: a certificate of insurance does not make someone an additional insured. Full stop.
A certificate of insurance (COI) is an evidence document. It confirms that a policy exists, lists the policy limits, and typically lists additional insureds — but it is not the policy itself, and it does not create or modify coverage. Courts have repeatedly held that certificates of insurance are informational only.
What creates additional insured status is the actual endorsement attached to the policy. This is a document your insurer generates and adds to the policy file. When clients or landlords require additional insured status, they should be asking for two things: a certificate of insurance and a copy of the actual endorsement form.
For more on how certificates of insurance interact with your general liability coverage — and what they do and don't guarantee — see how a certificate of insurance relates to general liability.
What to Do When You Receive an Additional Insured Request
The process is usually straightforward if you know what to ask for. Here's how to handle it without fumbling the contractual requirement.
- Review the contract language carefully. Does it require ongoing operations, completed operations, or both? Does it require primary and noncontributory language? Note the exact legal name the additional insured wants used — it has to match the endorsement.
- Contact your broker or insurer immediately. Don't wait until contract signing to request the endorsement. Processing takes time, and some insurers need advance notice for certain coverage modifications.
- Request the endorsement form in writing. Get the actual ISO form number or endorsement language, not just a verbal confirmation. Confirm primary and noncontributory status if the contract requires it.
- Issue the certificate of insurance with the endorsement attached. Send both documents to the requesting party. If they only receive a COI without the endorsement, there's no guarantee coverage will respond as expected.
- Confirm renewal continuity. Additional insured endorsements need to be renewed with the policy. Set a reminder to reissue certificates and confirm endorsement continuity at each renewal.
If you lease commercial space, the obligations run both directions — your landlord likely requires you to carry GL with them named as additional insured, while you may also have rights under their property coverage. Understanding the full picture of liability exposure in commercial space is worth reviewing. For broader liability risk that standard policies don't address, umbrella coverage for landlords fills in important gaps.
When You're the One Being Added to Someone Else's Policy
If you're the client or landlord on the other end of this transaction, your job is to verify — not just accept. Here's what to check before signing off:
- Is the endorsement actually attached to the policy? Request a copy of the endorsement form, not just the COI. Match the legal name on the endorsement to yours exactly.
- Does the coverage scope match what your contract requires? If you need both ongoing and completed operations coverage, confirm both ISO forms are present.
- Is primary and noncontributory language included? If your contract requires it, verify the endorsement explicitly states this — don't assume it's implied.
- What are the policy limits? Additional insured status gives you access to the named insured's limits, which may not be adequate for your exposure. If the contractor carries $1M per occurrence and a claim exceeds that, you're in trouble.
- When does the policy renew? Make sure you're tracking renewal dates so coverage doesn't lapse mid-contract.
Being an additional insured provides meaningful protection, but it's not a substitute for your own liability coverage. Your own policy needs to remain robust. For context on how endorsements work across different policy types — and how to evaluate which add-ons make sense — see filling coverage gaps with endorsements and riders.
Additional insured endorsements are one of the most consistently misunderstood tools in commercial insurance. The concept is simple; the execution has more moving parts than most people realize. Know what form is being attached, verify the language matches your contract, and don't rely on a certificate of insurance alone to confirm your protection is in place.
Frequently Asked Questions
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