The short version
- What it means: the other party gets rights under your policy for claims arising from your work.
- Why they ask: if someone sues them over your work, your insurance responds for them, and with primary wording it pays before theirs.
- It takes an endorsement. A certificate of insurance only shows coverage and cannot change the policy; the endorsement is what adds the party.
- Usually on general liability and auto. Washington's statewide IT contract requires it on those two; Idaho Department of Education standard terms require it on all policies except workers comp and professional liability.
- It travels with other terms: primary and noncontributory wording, waiver of subrogation, and notice of cancellation.
Additional insured vs other terms
| Term | What it does |
|---|---|
| Additional insured | Gives the other party rights under your policy for claims arising from your work |
| Certificate holder | Receives a certificate showing your coverage; gets no rights under the policy by being listed |
| Primary and noncontributory | Your policy pays first, without asking the additional insured's own insurance to share |
| Waiver of subrogation | Your insurer will not sue the other party to recover what it paid |
| Named insured | You, the business that bought the policy |
The endorsement you need
| Question | Why it matters |
|---|---|
| Blanket or scheduled? | A blanket endorsement usually covers anyone you agree in a written contract to add; a scheduled one names specific parties, each of whom must be added |
| Ongoing operations only, or completed operations too? | Construction contracts often require coverage after the job is finished, for injuries or damage that show up later |
| Who is covered and for what? | Since 2013, standard ISO endorsements cover the additional insured only for injury or damage caused, in whole or in part, by your acts or omissions or those of people working for you |
| Does it match the contract? | Contracts may require specific wording, form editions, or limits; one Washington DES project names ISO forms CG 20 10, CG 20 33, and CG 20 37 by edition |
Which policies contracts name
| Policy | Additional insured? | Examples |
|---|---|---|
| General liability | Standard request; required in all three state contracts we reviewed | Washington contract 14822; Idaho Department of Education standard terms; Washington DES project 2023-166 |
| Commercial auto | Often requested | Washington contract 14822; Idaho Department of Education; Washington DES project 2023-166 |
| Umbrella | Sometimes; Idaho Department of Education's clause covers all insurance except workers comp and professional liability | Check that the umbrella follows the additional insured terms |
| Professional liability (E&O) | Usually not; none of the three state contracts we reviewed require it | Idaho Department of Education and one Washington DES design-build project exclude it; 14822 requires it only on general liability and auto |
| Workers comp | No | Idaho Department of Education and Washington DES project 2023-166 exclude it; workers comp pays benefits to your own injured employees, so there is no liability coverage to add a client to (in Washington it comes from the state fund) |
Real contract terms
Washington's statewide IT contract 14822 requires that general liability and auto "include the State of Washington and all authorized Purchasers (and their agents, officers, and employees) as Additional Insureds evidenced by copy of the Additional Insured Endorsement attached to the Certificate of Insurance." It also requires the contractor's insurance to apply as primary without seeking contribution from the state's insurance, and a waiver of subrogation.
Idaho Department of Education standard terms say all insurance except workers comp and professional liability "shall be endorsed to name the State of Idaho and IDE as Additional Insured," and that the coverage "shall be primary."
Paste your contract into our contract insurance checker to list every additional insured and related requirement.
Common mistakes
- Sending a certificate without the endorsement. Many contracts, like 14822, ask for a copy of the endorsement itself.
- Missing completed operations on construction work.
- A scheduled endorsement that does not name the new client.
- An umbrella that does not follow the additional insured terms of the underlying policy.
- Promising additional insured status on E&O when the policy cannot provide it.