Additional insured is one of the most-required and least-understood terms in contracting. Getting it right is how you satisfy a contract and protect the people you work for; getting it wrong leaves everyone exposed.
What it actually is
Additional insured status is an endorsement on your liability policy that extends your coverage to another party, typically a client, general contractor, or property owner, for claims that arise out of your work. When a contract says the owner must be named as an additional insured, it is asking for this endorsement, not just a mention on a certificate.
Why the certificate is not enough
A certificate of insurance proves a policy existed when it was issued. It grants the holder no rights, and being listed as a certificate holder does not make a party an additional insured. The endorsement behind the certificate is what does the work. The most common mistake in construction risk transfer is treating the certificate as the protection.
Ongoing versus completed operations
There are two flavors that matter. Ongoing-operations additional insured covers the other party while you are working. Completed-operations additional insured extends that protection to your finished work after the job is done, which is exactly when many construction claims surface. Contracts for construction frequently require the completed-operations form, and a policy that provides only ongoing operations leaves a gap.
Both directions
You provide additional insured status to clients and GCs, and you require it from your subcontractors. The hiring contractor who collects sub certificates but never verifies the additional insured endorsement has not actually transferred the risk, and an uninsured sub becomes the GC’s claim.
The fix is simple: read the contract, confirm your policy carries the right endorsement, and verify what your subs provide. A coverage or contract review confirms it before a claim tests it.