An additional insured is a person or organization added to another party's liability policy by endorsement, so that the policy defends and pays claims against them arising from the named insured's work or premises. Landlords require it from tenants and vendors so that a claim caused by the tenant or vendor is handled by that party's insurer first.
Every commercial lease and vendor contract asks for it, and the phrase appears on almost every certificate. The IRMI definition is the short version: a person or organization not automatically included as an insured under a policy, who is included or added by endorsement.
Why it matters to a building
A slip-and-fall in a tenant's suite, a contractor's ladder through a lobby window, a cleaning crew's chemical spill: in each case the injured party may sue the building owner and the manager along with the party at fault. If the owner and manager are additional insureds on the tenant's or vendor's policy, that policy defends them. If not, the building's own general liability policy responds, and the loss lands on the owner's claims history and deductible.
Scheduled versus blanket endorsements
A scheduled endorsement names the additional insured specifically. A blanket endorsement covers any party the named insured has agreed in a written contract to add. Blanket forms are common and convenient, but they only work if the contract or lease actually contains the requirement, which is a reason to keep the insurance clause explicit. The additional insured endorsement entry at IRMI covers the standard forms.
What to check on review
| Check | Why |
|---|---|
| Endorsement copy attached | The certificate alone confers no rights |
| Correct legal entities named | Owner, manager, and lender as the lease requires |
| Ongoing and completed operations | Construction and trade contracts need both |
| Paired with primary and non-contributory | Otherwise both insurers may share the loss |
Additional insured status is usually required alongside primary and non-contributory wording and a waiver of subrogation. The three together are what most commercial leases mean by "the landlord's insurance requirements."
Related terms
Frequently asked questions
Why do landlords require additional insured status?
So that a claim arising from a tenant's operations or a vendor's work is defended and paid under the tenant's or vendor's policy rather than the building's. Without it, the landlord's own insurer responds first and the landlord absorbs the deductible and the loss history.
How is additional insured status verified?
By a copy of the endorsement, not by the certificate alone. The ACORD 25 description box may say the landlord is an additional insured, but the certificate confers no rights. The endorsement (a scheduled form naming the party, or a blanket form triggered by written contract) is the proof.
What is the difference between an additional insured and a certificate holder?
A certificate holder receives the certificate and, if the policy provides it, notice of cancellation. An additional insured has coverage under the policy. A landlord can be both; being only a certificate holder gives the landlord no protection under the policy.
Does additional insured status cover completed work?
Only if the endorsement extends to completed operations. Ongoing-operations forms cover claims while the work is in progress; a separate completed-operations endorsement covers claims after the vendor has finished. Construction and roofing contracts usually require both.