What is a certificate of insurance (COI)?

What information does a COI show?

Because nearly every certificate is the ACORD 25 (Certificate of Liability Insurance), the layout is consistent from one carrier to the next. A typical COI documents:

• The named insured (the business that holds the policy) and the producer (the agent or broker that issued it).
• Each line of coverage—commercial general liability, automobile liability, umbrella/excess, and workers’ compensation.
• Policy numbers and the effective and expiration dates for each policy.
• Limits of insurance, such as each-occurrence and general-aggregate limits.
• Checkboxes and notes indicating endorsements like additional insured and waiver of subrogation.
• The certificate holder—the third party receiving the document as proof of coverage.

Why does a COI matter for general contractors?

When a general contractor hires a subcontractor, the GC can be drawn into claims arising from the sub’s work—injuries, property damage, or auto accidents on the job. Collecting a certificate of insurance is the standard way to confirm, before work starts, that the subcontractor carries the coverage and limits the contract requires. If a sub is uninsured or underinsured, a loss can fall back on the GC’s own policy, raising premiums and exposing the business.

A certificate also documents whether the sub’s policy lists the GC as an additional insured and includes a waiver of subrogation and primary and non-contributory language—the contract terms that actually shift risk to the subcontractor’s carrier rather than the GC’s.

What are the limits of a certificate of insurance?

A COI is informational. The ACORD 25 itself states that it confers no rights on the certificate holder and does not amend, extend, or alter the coverage in the underlying policies. In practice this means a few things:

• The certificate is only accurate as of its issue date—coverage can be canceled or lapse afterward.
• The checkboxes for additional insured or waiver of subrogation summarize, but do not replace, the actual endorsement forms attached to the policy.
• To confirm that an endorsement truly applies, you generally need the endorsement form (for example, CG 20 10 or CG 20 38) or the full policy.

Common mistakes when reviewing COIs

Contractors who collect certificates by hand frequently miss the same issues: accepting a certificate with limits below the contract requirement; not noticing that a policy has already expired; assuming an additional insured checkbox is enough without verifying the endorsement form and whether it covers completed operations; and letting certificates go stale because no one tracks renewal dates. Each gap can leave the GC exposed at exactly the moment a claim arises.

How does Wardly help?

Wardly is free COI tracking software built for general contractors. Subcontractors upload their certificate from a link—no account to create—and Wardly reads the ACORD 25, checks limits, endorsements, and expiration dates against the requirements you set, and grades each certificate A–F automatically. If you’re comparing tools, see how it stacks up against myCOI and TrustLayer on the comparison hub.

This is general information, not legal or insurance advice.