What is Additional Insured? Definition & Compliance Guide

An additional insured is a person or entity that is extended protection under someone else's insurance policy, beyond the named insured who purchased the policy. When a contract requires a party to name you as an additional insured, that party's insurer agrees to defend and indemnify you - up to the policy limits - for claims arising from the named insured's operations.

This is one of the most frequently required - and most frequently mishandled - provisions in commercial contracting. Understanding exactly what it means, what it does not mean, and how to verify it is essential to real insurance compliance.

Why Contracts Require Additional Insured Status

When you hire a contractor, vendor, or tenant, you are exposed to liability that flows from their operations. A subcontractor's employee is injured on your property. A vendor's product causes harm at your facility. A tenant's negligence results in damage to a third party who then sues both the tenant and the building owner.

Without additional insured status, you must look to your own insurance to defend those claims. Your insurer pays. Your premium goes up. Your limits are consumed.

With additional insured status on the contractor's or vendor's policy, the claim is tendered to their insurer. Their coverage responds first. Your policy - and your premiums - are shielded from losses caused by someone else's operations.

This is the commercial logic behind the requirement. It is not paperwork formality. It is a transfer of financial risk.

How Additional Insured Status is Established

Additional insured status must be established by an endorsement to the underlying insurance policy - not merely by a statement on a certificate of insurance. This is a critical distinction.

An endorsement is a formal amendment to the policy contract. It changes the terms of coverage in writing. A certificate of insurance is a summary document; it can describe what endorsements exist, but it does not itself create coverage.

Common endorsements used to add additional insured status include:

• ISO CG 20 10 - covers ongoing operations
• ISO CG 20 37 - covers completed operations
• ISO CG 20 26 - used for designated owners, lessees, or contractors

Many contracts specify which endorsement forms are required. A contract that requires CG 20 10 and CG 20 37 is requiring coverage for both ongoing and completed operations. A COI that notes "additional insured as required by contract" without specifying the endorsement forms cannot confirm that the correct forms are in place.

Blanket vs. Scheduled Additional Insured

Additional insured status can be added in two ways:

Scheduled (specific) additional insured: The specific party is named in the endorsement. This requires a deliberate action for each relationship.

Blanket additional insured: The endorsement automatically extends coverage to any party the named insured is required by written contract to name as additional insured. This is more efficient for vendors and contractors managing many relationships.

Whether the blanket endorsement is in place - and whether it satisfies the specific contract's requirements - cannot be determined from the certificate alone. It requires reviewing the actual endorsement.

What to Check on a COI for Additional Insured Status

When reviewing a certificate of insurance for additional insured compliance, look for:

1. The additional insured notation - typically appears in the description of operations box or in checkboxes next to each coverage line
2. The correct entity name - the additional insured language must reference the correct legal entity as specified in your contract
3. The scope of coverage - ongoing operations only, or both ongoing and completed operations
4. The endorsement form number - if your contract specifies required forms, verify they are referenced
5. Whether primary and non-contributory language applies - additional insured status is often paired with primary and non-contributory requirements

Additional insured status on the general liability line does not automatically extend to other coverage lines. Contracts sometimes require additional insured status on commercial auto as well. Each line must be checked independently.

Common Compliance Failures

The most frequent problems encountered in contract-vs-COI review for additional insured requirements:

• The COI notes additional insured status, but no endorsement was actually issued
• The endorsement covers only ongoing operations when completed operations coverage is also required
• The additional insured named in the endorsement is a different entity than named in your contract
• The coverage is made available on a contributory basis rather than primary and non-contributory
• The blanket endorsement exists but requires a written contract to trigger - and no written contract was executed before work began

How Bramble Helps

Bramble extracts additional insured requirements from your contracts and compares them directly against submitted COIs, flagging missing endorsement references, scope gaps, entity name mismatches, and missing primary and non-contributory pairing. The comparison is automatic, auditable, and repeatable across every vendor relationship you manage.

See how Bramble handles contract-vs-COI compliance at scale. Visit getbramble.com.