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Endorsements2 min read · OCTOBER 21, 2025

Primary and Non-Contributory: The COI Wording That Trips Up

The CertifiKit team

Certificate-of-insurance desk

"Primary and non-contributory" means the vendor's insurance pays first and in full for a covered claim, and their insurer cannot ask your insurer to share the cost. It's a short phrase that decides whose policy actually absorbs a loss — and it's one of the most commonly required, and commonly missing, items in vendor insurance.

What problem does it solve?

When two liability policies cover the same loss, the default rule is that they share it on a pro-rata basis. So even when you're an additional insured on a vendor's policy, a claim could still pull in your own policy to pay part of the tab. Your premiums take a hit for the vendor's mistake.

Primary and non-contributory wording overrides that default. It does two things:

  • Primary: the vendor's policy responds first, as the lead policy, not as a co-payer.
  • Non-contributory: the vendor's insurer agrees not to seek contribution from your insurer, so your policy stays out of it entirely.

Where does it come from?

It's added by endorsement — for general liability, most often CG 20 01 — or written into the additional insured endorsement's terms. It frequently travels with two companions:

Requirement What it does
Additional insured Brings you under the vendor's policy
Primary & non-contributory Makes that policy pay first, alone
Waiver of subrogation Stops the insurer recovering from you later

Required together, these three turn a vendor's policy from "shares the loss with you" into "owns the loss."

How do I verify it on a COI?

On the ACORD 25 certificate, there's no dedicated checkbox for it, which is exactly why it gets missed. Look in two places:

  1. The Description of Operations box, for the literal phrase "primary and non-contributory."
  2. An endorsement form number such as CG 20 01 listed alongside the additional insured forms.

If the contract requires it but the certificate is silent, treat that as a gap — not a pass. For meaningful contracts, request the endorsement page to confirm the wording is actually on the policy.

Why it trips people up

The phrase doesn't have its own column on the certificate, so it lives in free-text where it's easy to overlook. A reviewer confirms the limits and the additional insured box, sees nothing obviously wrong, and approves a certificate that's quietly missing the one clause that keeps their own policy out of the claim.

That's the kind of buried, no-checkbox requirement the free CertifiKit checker is built to catch: upload a certificate and it scans the description text and endorsement signals for primary-and-non-contributory wording, compares it to your requirements, and flags it the moment it's absent — so it never slips through on certificate #50 of the season.

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