Primary and non-contributory describes how two policies interact. Primary means this policy responds first. Non-contributory means it will not seek contribution from the other party's own insurance before paying. Together they place the loss on one policy rather than splitting it. Like additional insured status, it is created by endorsement and not by wording on a certificate.
Updated September 2026.
Why brokers care
Contracts increasingly demand it, and it is one of the requirements most often noted on a certificate without being endorsed. The practical effect of getting it wrong only appears at claim time, when the client's own insurer is asked to contribute to a loss the contract said someone else would carry in full. That conversation happens years after the certificate was issued.
What to check
- That the endorsement exists, rather than a note on the certificate
- Whether the contract requires both primary and non-contributory, or only one
- How the endorsement interacts with any other insurance clause in the policy
- Whether it applies to all required lines or only general liability
- That the wording matches what the contract actually asks for
Common mistake
Accepting wording in the description of operations box in place of an endorsement. Text typed into that box by whoever produced the certificate has no effect on how two policies interact at claim time.
See how this sits in the wider certificate review checklist.