Blanket Additional Insured Definition & Compliance Guide

A blanket additional insured endorsement is a policy modification that automatically extends additional insured status to any party that the named insured is required by a written contract to name as an additional insured. Rather than listing specific parties by name in each endorsement, the blanket provision covers all qualifying relationships simultaneously - as long as the written contract requirement exists.

This endorsement is widely used by contractors, vendors, and service providers who manage large numbers of client relationships and cannot practically issue a separate scheduled endorsement for each one. Understanding how blanket additional insured works - and critically, what its limitations are - is essential to verifying that a vendor's COI actually satisfies your contract.

Blanket vs. Scheduled Additional Insured

Scheduled additional insured: A specific party is identified by name in the endorsement. Coverage applies to that party only. This is the most explicit form of additional insured coverage - there is no ambiguity about who is covered.

Blanket additional insured: No specific parties are named. Instead, the endorsement triggers automatically for any party the named insured is contractually obligated to include. This is more efficient for vendors with many client relationships, but it introduces conditions that must be verified.

For the party receiving the COI, the distinction matters because blanket coverage depends on conditions being met, while scheduled coverage is unambiguous.

The Written Contract Requirement

The blanket additional insured endorsement is triggered only when there is a written contract between the named insured and the additional insured that requires the named insured to provide additional insured status.

This creates a specific compliance risk:

• If work begins before a written contract is executed, the blanket endorsement does not apply for that early period
• If the relationship is governed by a purchase order, email, or verbal agreement rather than a formal written contract, the blanket endorsement may not trigger
• If the written contract does not explicitly require additional insured status, the endorsement may not apply

For organizations that engage vendors quickly or operate with informal agreements, this gap is material. A blanket endorsement on the vendor's policy is not coverage for you unless a qualifying written contract is in place.

Scope Limitations in Blanket Endorsements

Not all blanket additional insured endorsements are equal in scope. Key variations:

Ongoing operations only vs. ongoing and completed operations. Some blanket endorsements cover only the period during which the named insured is actively performing work. Others extend to completed operations - claims that arise after work is finished. Contracts that require completed operations coverage need a blanket endorsement that specifically includes it.

Causal trigger language. Many blanket endorsements limit additional insured coverage to claims "arising out of" the named insured's work. Some restrict this further to claims "caused by" the named insured's acts or omissions. The difference matters when the additional insured's own negligence contributes to a claim. More restrictive language may exclude the additional insured for claims where they are partially at fault.

Project-specific limitations. Some blanket endorsements apply only in connection with a specific project or location named in the underlying contract.

How to Verify Blanket Additional Insured Status on a COI

When a vendor submits a certificate of insurance noting blanket additional insured coverage, check:

1. Is the word "blanket" used, or is your entity specifically named? Both are acceptable, but blanket requires the additional verification below.
2. Is there a written contract in place that requires additional insured status? If work has begun without a signed contract, the blanket endorsement may not apply.
3. Does the blanket endorsement scope match the contract requirement? If the contract requires completed operations coverage, confirm the blanket endorsement includes it.
4. What is the specific endorsement form number? Request it from the broker if the COI does not note it. Proprietary blanket forms vary significantly in scope.
5. Does your contract specify a particular endorsement form? Some contracts require ISO CG 20 10 and CG 20 37 specifically, which are scheduled forms. A blanket form may not satisfy this requirement.

When to Request a Scheduled Endorsement Instead

For high-value or high-risk contracts, consider requiring a scheduled additional insured endorsement that names your entity specifically. This eliminates the ambiguity of blanket coverage and ensures that:

• Your specific legal entity is named
• The scope of coverage is clearly defined in the endorsement
• No written contract condition can jeopardize your coverage

For lower-risk vendor relationships, blanket coverage with a written contract in place is typically adequate.

How Bramble Helps

Bramble identifies whether your contracts require specific endorsement forms or accept blanket coverage, and checks submitted COIs for blanket additional insured language - flagging gaps in scope, missing endorsement references, and situations where a written contract may not yet be in place to trigger the blanket provision.

Visit getbramble.com to see how Bramble manages contract-vs-COI compliance at scale.