Blanket Additional Insured
Also known as: Blanket AI endorsement, Automatic additional insured endorsement, Blanket additional insured – where required by contract
A blanket additional insured endorsement is a single amendment to a liability policy — most often a general liability policy — that grants additional insured status to anyone the named insured is obligated by written contract to cover. Instead of the insurer issuing a new scheduled endorsement (and often charging premium) for each customer, landlord, general contractor, or municipality that demands to be named, the blanket form does it automatically the moment a qualifying contract is signed. Coverage typically attaches only to the extent required by that contract and only for liability arising out of the named insured's ongoing (and sometimes completed) operations, so the third party's protection tracks the actual indemnity bargain the two parties struck.
For a small business this matters because additional insured requirements are a routine gate to getting hired. A subcontractor bidding a job, a tenant signing a commercial lease, or a vendor contracting with a big-box retailer will usually be told to name the other party as an additional insured on a primary and non-contributory basis — see primary and noncontributory. A blanket form lets you satisfy that demand instantly and hand over a compliant certificate the same day, avoiding the delay and per-endorsement fees of scheduling each entity individually. The obligation to add them almost always flows from an insured contract containing a hold-harmless or indemnity clause, which is why underwriters scrutinize the contractual language before relying on the blanket wording.
A critical nuance is what a blanket endorsement is not. It is not the same as blanket insurance, a property concept where one limit floats across multiple locations or categories of covered property — the words "blanket" describe entirely different mechanics on the liability versus property side. It also differs from a plain scheduled additional insured, which names each entity explicitly and covers only those listed. Because a blanket form covers only parties you are contractually required to add, an entity you voluntarily agree to name in a handshake deal, or one added after a loss, may fall outside it. Buyers should also confirm whether the blanket wording extends to completed operations and whether it is truly primary and non-contributory, since a bare grant of additional insured status without those features often fails to satisfy the very contract that triggered it.
Real-world scenario
Summit Ridge Roofing LLC, a 14-employee commercial roofing contractor in Ohio, signs six to eight subcontract agreements a year with general contractors who each demand to be named as an additional insured on Summit Ridge's general liability policy. Rather than pay its broker $35 per scheduled endorsement and wait two days for each certificate, Summit Ridge adds a blanket additional insured endorsement to its $1,000,000 per-occurrence / $2,000,000 aggregate GL policy for a flat $450 annual charge. The policy premium itself is $18,600, and the blanket form automatically extends AI status to any GC it is required by written contract to add.
Mid-year, a Summit Ridge crew leaves a roof hatch open and rainwater damages a tenant's inventory. The tenant sues both Summit Ridge and the GC, Beacon Construction, for $640,000. Because the subcontract required primary and noncontributory coverage, Summit Ridge's insurer defends Beacon and pays first. Defense costs run $110,000, the claim settles for $425,000, and Summit Ridge's deductible is $5,000. Beacon's own insurer contributes $0 thanks to the P&NC wording, and a waiver of subrogation blocks Summit Ridge's carrier from recovering the $425,000 from Beacon.
Had Summit Ridge relied on scheduled endorsements and simply forgotten to add Beacon before the loss — a common gap — the GC would have been an uninsured party, exposing Summit Ridge to a breach-of-contract claim on top of the $425,000. The $450 blanket charge, versus roughly $280 in per-project fees plus administrative time, effectively bought automatic, gap-free compliance.
How it affects your premium
A blanket additional insured endorsement is priced as a modest add-on to the underlying liability premium, but several factors move that charge and whether an underwriter will even offer the form:
- Underlying GL premium and limits: The blanket charge is often a flat fee ($150–$600) or a small percentage of the base general liability premium, so higher limits and payroll drive it up.
- Trade and hazard class: High-risk operations like roofing, demolition, or structural work face higher blanket costs — or a scheduled-only requirement — because of frequent completed-operations exposure.
- Scope of the wording: Forms that grant primary and noncontributory status and completed-operations extension cost more than a bare ongoing-operations-only blanket.
- Contractual-trigger language: Broad "any party you are required by written contract to add" wording is priced higher than narrow forms limited to specific relationships.
- Loss history: Contractors with adverse loss runs or prior action-over claims may be surcharged or denied the blanket entirely.
- Waiver of subrogation inclusion: Bundling an automatic blanket waiver of subrogation raises the charge because the carrier surrenders recovery rights.
Common misconceptions
Myth: A blanket additional insured endorsement automatically covers everyone I do business with.
Reality: It only extends coverage to parties you are obligated to add by a written contract executed before the loss. Without a qualifying contract in place, an oral promise or a handshake deal grants no additional insured status at all.
Myth: Blanket AI coverage makes the other party primary, so my insurance never pays first.
Reality: The opposite is usually true — the blanket form typically makes your policy respond, and if the contract requires primary and noncontributory wording, your insurer pays before the additional insured's own coverage.
Myth: A blanket endorsement gives the additional insured the same protection as a scheduled one.
Reality: Blanket forms are governed by the endorsement's own trigger language, which can be narrower than a scheduled endorsement — for example, excluding completed operations. Always read the form wording rather than assuming parity.
Frequently asked questions
What is the difference between a blanket and a scheduled additional insured endorsement?
Does a blanket additional insured endorsement include completed operations?
Will a certificate of insurance prove I have blanket additional insured coverage?
Do I still need a written contract if I have blanket AI coverage?
Is blanket additional insured coverage more expensive than scheduled?
Sources cited
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