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Professional Liability (E&O) on a Certificate of Insurance: Which Vendors Need It

By SubCover HQ · Updated Nov 3, 2026 · 2 min read

General liability covers bodily injury and property damage from a contractor's work. It generally doesn't cover a bad design, a wrong calculation, or a missed defect in an inspection report. That's the job of professional liability, also called errors and omissions (E&O).

Who usually needs it

• Architects, engineers, and surveyors.
• Design-build and design-assist subs that produce drawings, calculations, or specs, such as fire sprinkler design, structural steel connections, or HVAC design.
• Inspectors and testing firms: home and building inspectors, special inspections, fire alarm and sprinkler inspection companies.
• Consultants: environmental consultants, energy auditors, and project managers who give advice rather than build.
• Some property vendors: IT and security system integrators, and companies that certify life-safety systems.

A painter or a landscaper usually doesn't need it. The question to ask is: are we relying on this vendor's advice, design, or judgment, not just their labor?

Where it shows on an ACORD 25

Professional liability isn't one of the printed rows. It normally appears in the blank "Other" row with its own insurer, policy number, dates, and limits (often shown as per claim and aggregate). If it's only mentioned in the description box, ask for the policy details.

What to check

1. Claims-made dates. Professional liability is usually written on a claims-made basis. The policy in force when the claim is made responds, so the vendor must keep coverage going after the job. Ask for the retroactive date, which should be on or before the date the vendor started work for you.
2. Limits. Per claim and aggregate, compared to your contract. Some policies reduce the limit as defense costs are paid, so ask your insurance professional what limit fits the work.
3. Continuing coverage. Many contracts require the vendor to keep professional liability in place for a set number of years after completion, or buy an extended reporting period if the policy ends.
4. Additional insured status. Professional liability policies typically don't add additional insureds the way general liability does. Don't hold up a vendor because the ADDL INSD box is blank on that line unless your contract specifically requires it and the agent confirms it's possible.

Tracking tip

Because professional liability is claims-made, an expired policy isn't just a paperwork gap. Coverage for past work may depend on the vendor renewing. Track the renewal like any other policy, and keep each year's certificate on file.

Key takeaways

Require professional liability from anyone whose design, advice, or inspection you rely on, check the retroactive date and limits, and keep tracking it after the job ends. SubCover HQ tracks every policy on a certificate, including the "Other" row, for $99/month.

Frequently asked questions

Does general liability cover professional mistakes?

Generally no. Most general liability policies exclude professional services such as design, engineering, and inspection advice.

Is professional liability usually claims-made?

Yes. Check the retroactive date and require the vendor to keep coverage in place after the work ends.

Can I be additional insured on professional liability?

Usually not. Professional liability policies typically don't add additional insureds the way general liability does.

Where does it show on a COI?

In the blank Other row on the ACORD 25, with the insurer, policy number, dates, and per-claim and aggregate limits.

This guide is general information, not insurance or legal advice. Policy wording varies; your insurance professional and attorney determine what you should require.