What Is a Certificate of Insurance?
A certificate of insurance (COI) is a document issued by an insurance company confirming that a vendor, contractor, or supplier carries specific insurance coverage, at specific limits, for a specific period. Businesses require a current COI from vendors, particularly those performing work on-site or providing services with liability exposure, before allowing them to begin work.
What a Certificate of Insurance Shows
- Type of coverage:
Commonly general liability, workers' compensation, auto liability, and umbrella or excess liability, depending on the nature of the vendor's work.
- Coverage limits:
The maximum amount the policy will pay per occurrence and in aggregate.
- Policy period:
The effective and expiration dates, which is the field most likely to lapse without notice.
- Named insured:
Confirming the certificate actually covers the specific vendor entity being engaged, not an affiliated but different entity.
- Certificate holder:
The business requesting the certificate, listed to confirm it was issued specifically for this relationship.
- Additional insured status:
When applicable, confirming the requesting business is named as an additional insured under the vendor's policy, extending some protection beyond just proof of the vendor's own coverage.
Why Businesses Require a COI Before Vendors Start Work
If a vendor causes property damage, injures someone, or is otherwise liable for a loss while working for or with a business, the business without proof of the vendor's insurance may find itself financially exposed if the vendor's coverage turns out to be inadequate, lapsed, or nonexistent. Requiring a COI before work begins shifts that risk back onto the vendor's own insurance, which is precisely why it is standard practice for any vendor with meaningful liability exposure, particularly those performing physical work on-site.
This is especially significant in construction and distribution, where vendors and subcontractors are routinely on a business's premises or job sites, creating direct liability exposure that a purely transactional supplier relationship would not.
The COI Verification Process
- Request the certificate before work or the relationship begins.
As part of vendor onboarding, not after the fact.
- Confirm coverage types and limits meet contractual requirements.
Matching the specific insurance requirements stated in the vendor agreement.
- Verify the named insured matches the vendor entity.
A certificate for a different but similarly named entity provides no actual protection.
- Note the expiration date and set a renewal tracking reminder.
Since coverage will lapse without an updated certificate on file.
- Confirm additional insured status where required.
Some contracts specifically require the requesting business be named as an additional insured, which is a distinct field from simply holding a copy of the certificate.
Why Expired Certificates Are a Common, Quiet Risk
A COI is a snapshot of coverage at a point in time, not an ongoing guarantee. Policies lapse, get canceled for non-payment, or simply expire and are not renewed, and unless a business actively tracks expiration dates across every vendor, an incident can occur while a vendor's coverage has already lapsed without anyone noticing until a claim is filed and there is nothing to collect against.
This risk compounds with vendor count. A business with a handful of on-site vendors can track expirations manually without much difficulty; a business with dozens or hundreds of active vendors, each with its own renewal date, cannot reliably do the same without a system actively flagging lapses before they become a live exposure.
Certificate of Insurance and Vendor Onboarding
COI collection belongs in the same vendor onboarding process that gathers a W-9 and banking details, described in supplier onboarding: it is verified once at the start of the relationship and then needs a mechanism to catch renewal before the existing certificate expires, rather than being treated as a one-time check that is never revisited for the life of the relationship.
Frequently Asked Questions About Certificate of Insurance
1. What is a certificate of insurance?
A certificate of insurance (COI) is a document issued by an insurance company confirming that a vendor carries specific insurance coverage, at specific limits, for a specific period. Businesses require a current COI before allowing vendors, particularly those doing on-site work, to begin work.
2. What should be checked on a certificate of insurance?
The type and limits of coverage, the policy period and expiration date, that the named insured matches the actual vendor entity, and whether the requesting business is listed as an additional insured where the contract requires it.
3. Why do businesses require a COI before vendors start work?
To confirm the vendor carries adequate insurance for potential liability, so that if the vendor causes damage or injury, their own coverage responds rather than exposing the business that hired them.
4. How often does a certificate of insurance need to be renewed?
Typically annually, matching the vendor's policy period, though the exact frequency depends on the vendor's specific coverage terms. A business needs to track each vendor's expiration date to catch renewal before the existing certificate lapses.
5. What happens if a vendor's insurance lapses without anyone noticing?
The business may be operating with a vendor it believes is insured but is not, creating financial exposure if an incident occurs during the lapse. This risk grows with vendor count, since manual tracking becomes unreliable across many vendors with different renewal dates.
6. Where does certificate of insurance verification fit in vendor management?
It belongs in the vendor onboarding process alongside collecting a W-9 and banking details, verified initially and then tracked for renewal for the life of the relationship rather than checked once and never revisited.
