Vendor Sent a COI Without Primary Noncontributory Endorsement — Here's What to Do

Your vendor emailed a COI. You open it, scan the Description of Operations box, and the words "primary and non-contributory" are nowhere. Or they appear in plain text but there's no endorsement number backing them up. Either way, you have a problem — and work is scheduled to start Monday.

By Nick Streicher, Founder, StrikeDocs. Published 2026-06-08.

This post explains exactly what the missing endorsement means, what it will cost you if a claim hits, and the fastest path to getting a compliant certificate without starting a fight with your subcontractor.

What "primary noncontributory" actually means — and what the COI box can't prove

Every general liability policy has a provision called "other insurance." When a claim involves multiple parties — say, your GL policy and your vendor's GL policy — the other-insurance clause determines which policy pays first and how much each carrier contributes.

Without a primary and noncontributory (P&NC) endorsement, your vendor's policy will try to share the loss with your policy on a pro-rata or excess basis. That means your carrier gets dragged into a claim caused entirely by your vendor's work. Your deductible erodes. Your loss runs get a mark. Your renewal premium moves.

A P&NC endorsement — typically manuscript language attached to the GL policy, or an ISO form like CG 20 01 — overrides that other-insurance clause. It tells the vendor's carrier: you are primary, and you will not seek contribution from the additional insured's policy. Full stop.

The critical thing to understand: a checkbox or a typed note in the Description of Operations box on an ACORD 25 is not an endorsement. The ACORD 25 is a summary document. It has no legal force of its own. A producer can type anything in that box. What matters is whether the actual policy form is attached to the policy. If the endorsement isn't on the policy, the note is worthless when the claim lands on an adjuster's desk.

If you need a refresher on what each section of the ACORD 25 actually represents, our ACORD 25 explainer walks through the form field by field.

Why your contract probably already requires it

Most standard subcontract agreements — and virtually every GC-drafted subcontract — include insurance requirements that specify:

The subcontractor's GL must name the GC (and often the owner) as additional insured.
That coverage must be primary and noncontributory with respect to the additional insured's own insurance.
The sub must provide evidence of these requirements before work begins.

If your contract includes that language (check Section 11 or the insurance exhibit), then a COI without a confirmed P&NC endorsement is a breach of the contract's insurance requirements — not just a paperwork preference. That distinction matters if you ever need to enforce the indemnification chain.

Before you send the rejection email, pull the contract. Confirm the exact language. Some contracts specify ISO form numbers; others just say "primary and noncontributory." Knowing what your contract requires determines whether you can accept a manuscript endorsement or need a specific ISO form.

What happens when a claim hits and the endorsement is missing

Here's the scenario: your electrical subcontractor's employee is injured on site. The sub's carrier pays the workers' comp claim. But the injured worker also sues you — the GC — for premises liability. Your GL carrier defends you. Then your carrier turns to the sub's GL carrier and says: you should be primary here. The sub's carrier looks at the policy, finds no P&NC endorsement, and invokes the other-insurance clause. Now both carriers argue about contribution. Litigation costs both sides money. Your carrier may ultimately recover some of it, but the claim still touches your loss runs.

Worse case: the sub's carrier successfully argues their policy is excess to yours. You pay first. You may never fully recover.

This is not a theoretical risk. It is the exact scenario that P&NC endorsements exist to prevent, and it is why every sophisticated owner and GC has made the endorsement a hard requirement since at least the mid-2000s.

How to read the endorsement schedule to confirm it exists

The COI is not where you confirm the endorsement. The endorsement schedule — the list of attached forms on the policy's declarations page — is where you confirm it. Request the following from your vendor's broker:

The declarations page for the GL policy, which lists all attached endorsements by form number and edition date.
The endorsement itself — the actual page that modifies the other-insurance clause.

If the broker resists providing the dec page, that's a red flag. A legitimate broker should be able to email an endorsement copy in under 15 minutes.

What you're looking for on the dec page:

ISO form CG 20 01 (Additional Insured — Primary and Noncontributory, various edition dates) — this is the cleanest confirmation.
A manuscript endorsement titled something like "Primary and Noncontributory Liability" with explicit override of the other-insurance clause.
ISO CG 20 10 or CG 20 37 (scheduled or blanket additional insured forms) — note that these confer additional insured status but do not automatically make coverage primary and noncontributory. The sub needs a separate P&NC endorsement or a combined form.

You can verify what CG 20 10 actually does — and doesn't do — using StrikeDocs' CG-20-10 endorsement decoder before you have the conversation with the broker.

If you find CG 20 26 (additional insured — designated person or organization) without a P&NC endorsement, same problem. The CG-20-26 decoder can confirm what that form covers.

Here's an example of what StrikeDocs returns when it processes a policy that has the additional insured endorsement but is missing the P&NC confirmation:

ISSUE: Primary & Noncontributory endorsement not confirmed on GL policy
FIELD: Description of Operations / Endorsement Schedule
SEVERITY: HIGH — typed notation in Description of Operations does not substitute for policy endorsement; other-insurance clause not overridden

That output is the difference between a COI review that catches the gap and one that waves the certificate through because it "looks fine."

What we learned running 59 real COIs through StrikeDocs

We processed 59 certificate documents through StrikeDocs — a mix of GC-collected subcontractor COIs from several active projects. The findings are not encouraging:

Primary & Noncontributory was confirmed on only 15.5% of policies. That means more than 84% of the policies in this corpus had no confirmed P&NC endorsement — either missing entirely or present only as a typed note with no backing endorsement on the policy.
Additional Insured status was confirmed on only 33.9% of policies. P&NC is meaningless without AI status, but AI status without P&NC leaves you exposed to the contribution problem described above. Less than a third of policies had both confirmed.
Waiver of Subrogation was confirmed on only 21.3% of policies. This is the third leg of the stool — P&NC, AI, and WOS typically travel together in a well-drafted subcontract. Getting all three confirmed on the same COI was rare in this corpus.

These numbers reflect what GC offices are actually receiving, not what contracts are requiring. The gap between contractual requirement and delivered documentation is large, and it is consistent across states. In this corpus, New York (16 documents) and California (10 documents) were the most represented states — both high-litigation environments where the P&NC gap carries the most exposure.

If you're managing a subcontractor portfolio and want to run your own COIs through the same audit, the batch COI audit tool processes multiple certificates at once and flags P&NC, AI, and WOS gaps by policy line.

How to request the correction without torching the relationship

The most common mistake GC office managers make when a COI comes in deficient: they send a vague rejection email that says something like "your certificate doesn't meet our requirements." The sub forwards it to their broker. The broker has no idea what's wrong. Three days pass. Nobody starts work.

Be specific. Here is language that works:

"Your current COI does not confirm a Primary and Noncontributory endorsement on your GL policy. A typed note in the Description of Operations is not sufficient — we need the actual endorsement form number (e.g., CG 20 01 or equivalent manuscript form) confirmed on the declarations page or a copy of the endorsement. Please have your broker email the endorsement copy and updated COI to [address] by [date]."

That email can be answered in one phone call between the sub and their broker. The broker adds the endorsement to the policy (if it isn't already there) or sends the dec page confirming it exists. Total elapsed time: 24–48 hours if you don't have to chase.

If the broker says the endorsement "isn't available" on their policy form: that is a carrier-level limitation. Some admitted carriers, particularly smaller or non-standard markets, do not offer P&NC endorsements. That is a legitimate problem — and the answer may be that the sub needs a different carrier to perform work on your project. That's a business conversation, not an administrative one, and it should involve your risk manager or insurance counsel.

When a description-of-operations note is and isn't enough

This comes up constantly: the sub's broker types "coverage is primary and non-contributory" in Box 27 of the ACORD 25. Is that enough?

The short answer is no, and here's why: the ACORD 25 certificate contains an explicit disclaimer, printed on the form, that the certificate does not amend, extend, or alter the coverage afforded by the policies. ACORD has published guidance reinforcing that certificates are informational documents only. The certificate holder's rights are governed by the policy, not by the certificate.

The longer answer is: it depends on what your contract says and what jurisdiction you're in. A handful of courts have found that certificates with specific representations can create coverage expectations — but this is not a reliable strategy and it requires litigation to establish. You do not want your coverage to depend on a court case.

If you're in a situation where the sub's broker is pushing back and saying the typed note is standard practice, escalate. Request the actual endorsement. If the endorsement doesn't exist on the policy, the typed note is not a substitute.

For a deeper look at how subcontractor COI compliance works across a full project, our subcontractor insurance verification guide covers the full workflow including how to track outstanding items at the portfolio level.

The audit checklist: primary noncontributory + the two endorsements it travels with

When you receive a COI from a vendor or subcontractor, run through these three items before accepting it:

1. Additional Insured (AI) — confirmed on policy, not just checked on ACORD

Look for an endorsement form number in the Description of Operations or request the dec page.
Acceptable: CG 20 10, CG 20 26, CG 20 33, CG 20 37, or a blanket AI endorsement.
Not acceptable: the box checked with no endorsement form referenced.
Quick check: CG-20-10 decoder or CG-20-33 decoder.

2. Primary and Noncontributory — confirmed endorsement on GL policy

Look for CG 20 01 or equivalent manuscript form on the dec page.
A typed note in Description of Operations is not acceptable standing alone.
If the policy is a BOP or package, confirm the P&NC language applies to the GL component.

3. Waiver of Subrogation (WOS) — confirmed on GL and WC

For GL: look for CG 24 04 or manuscript WOS endorsement.
For Workers' Comp: look for WC 00 03 13 (the NCCI standard WOS form).
WOS on WC is often forgotten; your contract probably requires it on both lines.
Quick check: CG-24-04 decoder and WC-00-03-13 decoder.

If all three are confirmed with actual endorsement backing, the COI passes this layer of the review. If any one of the three is missing or unconfirmed, send the correction request before clearing the vendor to work.

For projects with multiple active subs, tracking these three items manually across dozens of COIs is where things fall through the cracks. The batch COI audit tool runs all three checks simultaneously across your full subcontractor list and surfaces the gaps by vendor.