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Certificates of insurance, additional insured and waivers, explained
A certificate of insurance is a one-page ACORD 25 summary that proves your policies exist, but it doesn't add anyone to them. When a GC or property manager asks for additional insured, a waiver of subrogation or primary and non-contributory wording, each one needs an endorsement on your policy. Here's what each request means, how fast you should get the paperwork, and which contract clauses to question before you sign.
Key takeaways
- A certificate of insurance (COI) is proof, not coverage. The ACORD 25 says on its face that it does not amend, extend or alter your policies.
- "Additional insured," "waiver of subrogation" and "primary and non-contributory" are three separate endorsements on your policy. A checked box on the certificate means little without them.
- A plain COI on coverage you already have should be a same-day request from a good agent. New endorsements take longer and may add premium.
- Read the contract's insurance exhibit before you sign. Broad indemnity, pollution requirements and umbrella limits are where plumbers get stuck.
- A GC asking for additional insured status is a sign bigger contracts, and bigger limits, are coming.
What a certificate of insurance for contractors actually is
A certificate of insurance (COI) is a one-page snapshot of your coverage on the day it prints. For liability, the standard form is the ACORD 25. It lists your agent (the "producer"), your carriers, your policy numbers, your dates and your limits, including your general liability and commercial auto.
Say you just won a job, and the general contractor (GC) sends a one-line email: "Send your COI with additional insured and waiver of sub before you start." Part of that request is a form your agent can print. The other part lives inside your policy, and that's where start dates slip.
The ACORD 25 tells on itself. Its header says it is issued "as a matter of information only" and does not amend, extend or alter the coverage of the policies listed. A line just below adds that if the holder is an additional insured, the policy must be endorsed.
Some states put this into law. New York Insurance Law 502 says a certificate can't expand or rewrite the policy it refers to.
Texas Insurance Code chapter 1811 bars carriers and agents from issuing a certificate that does that, and Texas requires certificate forms to be filed with and approved by the Texas Department of Insurance.
If you work in either state, see New York plumber insurance and Texas plumber insurance.
So here's the plain rule. The certificate is the receipt. The endorsements are the coverage. If the GC's name sits on the COI but not on your policy, the GC may have nothing to stand on when a claim comes in. That's why careful GCs ask for the endorsement pages, too.
Every ACORD 25 has two narrow columns marked "ADDL INSD" and "SUBR WVD." Your agent should mark those only when the matching endorsement is actually on your policy.
What the GC means by additional insured and waiver of subrogation
Each phrase in that GC email is a different endorsement, usually on your general liability policy. That includes the "primary and non-contributory" line. They do different jobs, and none of them replaces the others.
Additional insured (CG 20 10 and CG 20 37)
Additional insured (AI) status puts the GC on your policy for claims that come from your work. Say a tenant slips on a wet floor next to your water heater swap and sues the GC. With AI status, your policy may defend the GC, depending on its wording.
Most GCs want it two ways. ISO form CG 20 10 covers ongoing operations, meaning work in progress. CG 20 37 covers completed operations, which means damage that shows up after you've finished the job.
For plumbers, the second form matters a lot. A cleanout cap that backs sewage into a tenant's unit six months after you leave is a completed-ops claim.
Waiver of subrogation (CG 24 04)
Subrogation is your insurer's right to go after someone else to get back what it paid on a claim. A waiver of subrogation means your insurer gives up that right against the GC. On general liability, the usual ISO form is CG 24 04.
GCs often want the same waiver on your workers' comp policy. One large GC's subcontract exhibit names form WC 00 03 13 for most states and a separate form for Texas.
Primary and non-contributory (CG 20 01)
This settles whose insurance pays first. "Primary" means your policy responds before the GC's. "Non-contributory" means your carrier won't ask the GC's carrier to chip in. The ISO form is CG 20 01, and it's a separate endorsement from the AI form.
Blanket vs. scheduled additional insured endorsements
A scheduled endorsement names one GC or owner on your policy. A blanket endorsement adds anyone you agreed in a written contract to add. For a plumber who works for six GCs and three property managers a year, blanket usually wins. You skip the call to your agent every time a new contract shows up.
ISO writes both kinds. CG 20 10 and CG 20 37 are often used as scheduled forms, with names on a list. For blanket status, form CG 20 33 adds anyone a written construction contract says you must add. Form CG 20 38 goes one step further. It can reach parties above the GC, like the building owner, that the contract says you must cover.
Blanket forms come with fine print. They generally need a written contract that asks for AI status, so a handshake job for a property manager may not count.
Some AI forms only cover work in progress, so check that yours also reaches completed operations. And some GCs still want their name on a scheduled form, so they may reject a blanket cert.
Ask your agent which AI forms your policy carries right now. Many contractor policies include a blanket form, and some don't. That one answer tells you whether the next COI request takes an hour or a week. If you hire 1099 subs, collect their COIs the same way GCs collect yours. Our guide to 1099 subcontractors and workers' comp explains why, and how workers' comp audits work shows what a missing sub certificate can cost.
How to get a certificate of insurance, and how fast
A plain certificate on coverage you already have should be a same-day job from a good agent. For our current clients, it is: certificates on existing coverage are available the same day. New endorsements take longer because they change your policy. They may need the carrier to sign off, and some add premium. Four steps get the COI right the first time.
- Send the insurance exhibit. Forward the contract's insurance section to your agent, not just the GC's email. The exhibit lists the limits, the forms and the exact names.
- Give exact legal names. Use your entity name as it reads on your policy, and the GC's name as it reads on the contract. An "LLC" where the contract says "Inc." is a common reason a COI bounces.
- Confirm the endorsements. Ask which endorsements are on the policy now and which need to be added. Ask for copies of the endorsement pages to send with the COI.
- Track your dates. A COI is only good until each listed policy expires. Ask your agent to send new certificates to every active GC at renewal.
Speed is a fair test of your agent. A plain COI is routine paperwork and should never hold up a start date. If you wait three days for a simple certificate, that cost lands on your schedule, not your agent's. If that keeps happening, request a free, no-obligation quote and let us show you how we handle certificates.
Red flags in contract insurance clauses
Most COI trouble starts with a contract signed before anyone read the insurance exhibit. Read it before you sign, and send it to your agent the same day. These are the clauses that trip up plumbers most.
Broad indemnity
Some contracts make you cover the GC even for the GC's own fault, and many states limit this. Texas Insurance Code chapter 151 voids many of these clauses in construction contracts and limits AI requirements to match.
California Civil Code 2782 voids clauses that shift an owner's active negligence onto a contractor.
If you work there, see California plumber insurance. Rules vary by state, so have an attorney review the indemnity clause before you sign.
"No exclusions beyond the standard form"
One large GC's published subcontract exhibit asks for exactly that.
Some contractor GL policies add exclusions, such as for mold or underground work. If yours does, you may not be able to promise that clause as written.
Pollution and mold coverage
That same exhibit asks plumbing and other MEP trades to carry contractors pollution liability, with mold coverage included.
Standard GL policies carry a pollution exclusion, so this can mean a separate pollution liability policy.
Per-project aggregate
The contract may say your aggregate limit must apply "separately to the Project." That takes an endorsement, and not every policy has it.
Edited certificate wording
A GC may ask your agent to type promises onto the COI, like 30 days' notice of cancellation. The ACORD 25 says notice goes out according to the policy's own terms.
In New York and Texas, a certificate can't add terms the policy doesn't have.
Why a COI request means you're ready for bigger limits
When the GC becomes an additional insured, it shares your limits. Under the ISO AI wording used since 2013, the GC's coverage is capped at the lesser of what the contract requires and what your policy's limits allow.
One bad claim against both of you can eat into the same $1 million.
That's why commercial exhibits push limits up. The GC exhibit cited above asks for $1 million per occurrence and $2 million aggregate on GL. It also asks for a $5 million umbrella that follows the form of your GL, auto and employer's liability.
An umbrella policy adds a layer of limits above those policies.
If a property manager or GC asks for AI and a waiver of subrogation today, a bigger contract with bigger limits is usually close behind. That's the time to price an umbrella, not the week a bid is due. Ask your agent whether the umbrella extends to your additional insureds, since exhibits like that one expect it to follow your GL. It's also a good time to check your completed-operations limit, since plumbing claims often show up after you've left.
For the full picture of what GC work asks of a growing shop, from endorsements to performance and payment bonds, see insurance for commercial and new construction plumbers. The certificate is the easy part. Getting the right endorsements and limits on your policy before you need them is the work, and it's the step that lets you say yes to the next contract.
Frequently asked questions
How long does it take to get a certificate of insurance?
Does adding an additional insured cost money?
What's the difference between a certificate holder and an additional insured?
Can a contractor use one COI for every job?
What's the difference between an ACORD form and an insurance policy?
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