Certificate of Insurance for Plumbers: What’s on It, How to Get One, and When You Need It
A certificate of insurance (COI) for a plumbing business is a one-page ACORD 25 document that summarizes your active coverage: the carriers, policy numbers, coverage types, limits, and effective dates. It does not grant coverage to anyone who receives it. It is a snapshot of your policy, issued by your insurance agent on request, at no additional cost. Most licensing boards, general contractors, and commercial clients require it before allowing work to begin or issuing a license.
One of the most common misunderstandings in contractor insurance is the difference between being listed as a certificate holder versus being named as an additional insured. They are not the same thing, and conflating them has led to uncovered claims. This guide covers what a plumber’s COI actually contains, which states require submission to a licensing board, how to name a GC as additional insured the right way, and how to get your ACORD 25 the same day you need it.
What a Certificate of Insurance for Plumbers Actually Contains
The ACORD 25 is a standardized certificate developed by the Association for Cooperative Operations Research and Development (ACORD). It has been the industry standard for commercial insurance certificates for decades. Every field on the form has a specific meaning, and errors in any of them can cause a certificate to be rejected by a licensing board or GC.
The Key Fields on an ACORD 25 for Plumbing Contractors
- Producer (Box 1): Your insurance agency’s name and contact information — The Allen Thomas Group for ATG policyholders, not the insurance carrier directly.
- Insured (Box 4): Your legal business name exactly as it appears on your contractor license. If your business operates under a DBA, confirm with your agent whether the DBA or legal entity name is required by the requesting party.
- Insurance coverage sections (GL, Auto, Workers Comp, Umbrella): Each active policy is listed with the carrier’s name, NAIC number, policy number, and effective/expiration dates. Coverage limits (per occurrence, aggregate, etc.) appear here.
- Certificate Holder (Box 27): The party requesting the COI. Their exact legal name and address must appear here. This is different from additional insured status.
- Cancellation notice: Standard certificates include a 30-day cancellation notice clause. Some GCs require 30-day notice; government contracts sometimes require 60 days. Your agent can modify this with a carrier endorsement if the contract requires it.
The ACORD 25 does not show policy exclusions, endorsements, or conditions. It confirms coverage exists at the limits shown, as of the issue date. For full policy terms, the requesting party would need to review the actual policy or specific endorsements.
When Plumbers Are Required to Show a Certificate of Insurance
There are three distinct contexts in which a plumbing contractor will be asked for a COI, and each context has different requirements for what must appear on the certificate.
1. State Licensing Board Submission
Several states require COI submission directly to the licensing authority as part of the license application or renewal process. The certificate holder line must name the specific state board, not a general GC or client.
| State | Governing Board | COI Requirement | Certificate Holder |
|---|---|---|---|
| Texas | Texas State Board of Plumbing Examiners (TSBPE) | Required for Responsible Master Plumber (RMP) license | Texas State Board of Plumbing Examiners |
| Minnesota | Minnesota Department of Labor and Industry (DLI) | Required for plumbing contractor license application | State of Minnesota, Department of Labor and Industry |
| Maryland | Maryland Board of Plumbing | Required; certificate must include registrant’s license number | Maryland Board of Plumbing, DLLR |
California’s Contractors State License Board (CSLB) requires licensed contractors to carry workers compensation insurance and submit a COI with CSLB listed as certificate holder when renewing or obtaining a license that involves employees. California plumbing contractors can verify current requirements at the CSLB website.
2. General Contractor or Property Manager Requirements
Most GCs require subcontractors to provide a COI before starting work on any project. The GC’s standard subcontractor agreement will specify the minimum coverage types, per-occurrence limits, and whether additional insured status is required. Typical GC requirements for plumbing subs include: $1M per occurrence GL, $2M aggregate, workers comp at state statutory limits, and commercial auto. Some larger commercial GCs require $2M per occurrence or a $5M umbrella above the base GL.
3. Client or Property Owner Requests
Residential clients, property management companies, and commercial building owners may request a COI before allowing a plumber to begin work. These requests typically do not require additional insured status unless the client’s attorney or property manager specifies it in a formal contract. For one-off residential jobs, a COI showing the client as certificate holder is usually sufficient.
Certificate Holder vs. Additional Insured: Why the Distinction Matters
Being named as a certificate holder on a plumber’s COI means you receive a copy of the document and notification if the policy cancels. It does not give you any coverage under the policy. Additional insured status is an endorsement added to the underlying policy that extends certain coverage rights to the named party. General contractors who require "additional insured" status in their subcontract agreements are entitled to that endorsement, not just a certificate that lists their name.
The practical consequence: if a plumbing subcontractor causes water damage that injures the GC’s project, and the GC is only a certificate holder, the GC cannot make a claim under the plumber’s GL policy. They would need to pursue the plumber directly or rely on their own policy. If the GC had been properly added as an additional insured, their legal defense and covered damages could be addressed under the plumber’s GL policy up to the policy limits.
How to Add a GC as Additional Insured
The process requires three steps: request the additional insured endorsement from your agent when you provide the GC’s information, confirm the endorsement language matches what the GC’s contract specifies (some GC contracts specify ISO form CG 20 10 or CG 20 37), and then have the COI issued with the AI endorsement confirmed. The ACORD 25 will show the additional insured endorsement in the "Description of Operations" section (Box 17) with language such as: XYZ General Contracting, Inc. is included as Additional Insured per CG 20 10 04 13 where required by written contract.
How to Get a Certificate of Insurance for Your Plumbing Business
- Confirm your policy is active. A COI can only be issued against coverage that is currently in force. If your policy expired or you are in the process of switching carriers, the COI cannot be generated until the new policy binds.
- Identify the certificate holder exactly. Get the requesting party’s full legal business name and address. A COI submitted to a licensing board with an incorrect entity name will be rejected. If the requester is a state board, use the exact name as shown on the board’s official documentation.
- Determine if additional insured status is required. Read the contract or project agreement. If it says "additional insured," notify your agent before the COI is issued so the endorsement can be added to the policy first.
- Submit the request to your insurance agent. Provide the certificate holder information, any required additional insured language, and any specific coverage limit requirements. Your agent generates the ACORD 25 form.
- Review the certificate before submitting. Verify the insured name matches your license exactly, the coverage limits meet the contract minimum, and the certificate holder details are correct. Errors in any of these fields can cause rejection.
At The Allen Thomas Group, COIs are issued same-day for active policyholders. We cover plumbing contractors across 27 states and work with multiple A-rated carriers, which means we can often bind new coverage and issue a COI within the same business day for standard plumbing risks.
Common COI Errors That Cause Rejection or Coverage Gaps
- Wrong insured name: The name on the COI must match the business name on the contractor license exactly. "Smith Plumbing LLC" and "Smith Plumbing" are different entities to a licensing board.
- Expired certificate: COIs show the policy effective and expiration dates. A certificate issued against a policy expiring next month will be outdated within weeks. Licensing boards that hold certificates on file may flag expiration at renewal time.
- Certificate holder listed as additional insured without endorsement: The most consequential error. Never assume being listed as certificate holder provides coverage. Verify with your agent that the endorsement is on the policy before representing AI status on a COI.
- Insufficient coverage limits: A contract requiring $2M per occurrence and a COI showing $1M per occurrence is a compliance failure, not a paperwork issue. Always confirm the required limits before requesting the certificate.
Related Plumbing Insurance Guides
Frequently Asked Questions
Is a certificate of insurance the same as proof of insurance?
A COI is the standard form of proof of insurance for contractors and businesses. For most licensing boards and GC requirements, the ACORD 25 is the accepted format. The declarations page or an endorsement document can also serve as proof, but the ACORD 25 is the universally recognized format in the contracting industry.
Can I list my client as an additional insured?
Yes, but additional insured status requires a policy endorsement, not just a name on the certificate. Your agent must add the AI endorsement to the underlying policy before the COI is issued confirming that status. Certificate holder designation alone provides no coverage to the requesting party.
Does getting a COI cost extra?
No. A certificate of insurance is issued at no additional cost once your policy is active. The Allen Thomas Group issues COIs at no charge for all active policyholders.
How long does it take to get a COI?
Same-day with an active policy. If you need coverage and a COI on the same day, that can also be arranged for standard plumbing risks. Call (440) 826-3676 to start the process.
What information appears on a plumber’s certificate of insurance?
The ACORD 25 shows your business name, insurance agency name, carrier names and NAIC numbers, policy numbers, coverage types and limits, effective/expiration dates, and the certificate holder’s name and address. Policy exclusions and full endorsement language do not appear on the certificate.
Which states require plumbers to submit a COI to their licensing board?
Texas (TSBPE), Minnesota (DLI), and Maryland (Board of Plumbing) are three states with documented COI submission requirements for plumbing contractor licensing. California’s CSLB requires workers compensation proof for licensed contractors with employees. Requirements change, so verify current specifics with the relevant state board before submission.
What is the difference between certificate holder and additional insured?
Certificate holder status means the party receives the COI and cancellation notices. Additional insured status means the party is added to the policy by endorsement and can make claims under your policy. GC contracts that specify "additional insured" require the endorsement, not just certificate holder designation.
Can I use the same COI for multiple clients?
No. Each COI names a specific certificate holder. You need a separate COI issued for each client, GC, or licensing board that requests one. Your insurance agent can issue multiple COIs as needed at no additional cost.
Need a COI Today? We Issue Same-Day for Active Policyholders
The Allen Thomas Group is an independent agency serving plumbing contractors across 27 states. We work with multiple A-rated carriers and can often bind new coverage and issue your ACORD 25 certificate within the same business day for standard plumbing risks.