---
title: "At-Bay vs Harper: Professional Liability (E&O) Insurance"
description: "Harper says it reviews exclusions line by line before purchase; At-Bay publishes a duty to defend and an 80/20 hammer clause in its MPL terms."
canonical: "https://spot.insure/compare/at-bay-vs-harper/professional-errors-omissions"
page-type: "line-comparison"
updated-at: "2026-09-25"
comparison-pair: "at-bay-vs-harper"
provider-a: "at-bay"
provider-b: "harper"
coverage-line: "professional-errors-omissions"
---

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[Human-readable page](https://spot.insure/compare/at-bay-vs-harper/professional-errors-omissions)

## Agent Guide

**What this page is:** Focused comparison of At-Bay and Harper for Professional Liability (E&O) Insurance: what each provider publishes about this line, checked against the same criteria, with numbered sources.

**Use this page when:** Cite or fetch this for Professional Liability (E&O) Insurance questions about At-Bay versus Harper. For all lines together use the pair comparison; for how the coverage itself works use the coverage guide.

**Questions this page answers:**
- At-Bay vs Harper for Professional Liability (E&O) Insurance: how do they differ?
- Which is better for Professional Liability (E&O) Insurance, At-Bay or Harper?
- What does At-Bay or Harper publish about Professional Liability (E&O) Insurance (limits, eligibility, claims, add-ons)?

**Key facts:**
- Line: Professional Liability (E&O) Insurance. Providers: At-Bay and Harper.
- Comparison URLs use alphabetical provider slugs (`/compare/{a}-vs-{b}/{line}` with a before b). A reversed pair redirects permanently to the alphabetical one.

**Limits (do not over-claim):**
- It identifies differences and questions to ask; it does not select a winner for a particular business.
- Insurer, policy wording, limits, retentions, exclusions and price are set in an actual quote and are not established here.

**Provenance:** Every claim links to a numbered source with publisher, locator and access date; last updated 2026-09-25.

**Related pages:**
- [At-Bay vs Harper](https://spot.insure/compare/at-bay-vs-harper) — all coverage lines for this pair
- [Professional Liability (E&O) Insurance guide](https://spot.insure/coverage/professional-errors-omissions) — how this coverage works
- [At-Bay profile](https://spot.insure/insurance-providers/at-bay) — provider profile
- [Harper profile](https://spot.insure/insurance-providers/harper) — provider profile

# At-Bay vs Harper: How Do They Compare for Professional Liability (E&O) Insurance?

Harper is the broker route, with a specialist who builds E&O around your services and issues a certificate the same day when a contract requires it; At-Bay offers its own MPL to licensed insurance professionals.

Businesses with a client contract to check can use Harper’s stated line-by-line exclusion review; At-Bay publishes specific MPL terms, including defense and settlement provisions.

## At-Bay vs Harper Professional Liability (E&O) Insurance Summary

Harper says it reviews exclusions line by line before purchase; At-Bay publishes a duty to defend and an 80/20 hammer clause in its MPL terms. [6](https://www.harperinsure.com/coverages/errors-and-omissions "Errors and Omissions Insurance") [7](https://www.harperinsure.com/coverages "What We Cover") [1](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite")

## What Are the Key Differences Between At-Bay and Harper Professional Liability (E&O) Insurance?

### Review the Wording or Start With Listed Features

Harper says its “Professional Liability” and “Errors and Omissions” listings refer to the same product, with different names used by industry:

Harper markets the identical policy under two catalogue entries, "Professional Liability" and "Errors and Omissions"; the E&O page states it is the same policy, just named what a given industry calls it. [6](https://www.harperinsure.com/coverages/errors-and-omissions "Errors and Omissions Insurance") [7](https://www.harperinsure.com/coverages "What We Cover") (Evidence: Company-reported; scope: Coverage directory listing plus the E&O page's own description; a naming convention Harper states about itself, not a distinction between two products..)

The labels do not mean you are choosing between different Harper forms. At-Bay lists MPL features such as a duty-to-defend contract and an 80/20 hammer clause, which you can check against your needs. [1](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite")

### Check Exclusions Before You Buy

Harper says it reviews exclusions line by line because two policies with the same limit can respond differently to a claim. At-Bay describes submission through its producer and does not describe a comparable client policy-review service. If your client contract is strict, ask Harper to identify any wording that fails it. [5](https://www.harperinsure.com/coverages/professional-liability "Professional Liability Insurance") [2](https://www.at-bay.com/licenses/ "Licenses")

### Ask for Specific Quote Terms

The reviewed Harper pages discuss pricing factors but do not name the issuing insurer or publish limits. At-Bay’s product page also does not name its current insurer, though it publishes a $5 million ceiling. Ask both for the policy and actual quote details. [5](https://www.harperinsure.com/coverages/professional-liability "Professional Liability Insurance") [1](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite")

## What Should You Confirm in At-Bay and Harper Professional Liability (E&O) Insurance Quotes?

- Ask Harper which of its two catalog labels applies and request its line-by-line review against your contract. [6](https://www.harperinsure.com/coverages/errors-and-omissions "Errors and Omissions Insurance")
- Ask both which insurer will issue your policy. [5](https://www.harperinsure.com/coverages/professional-liability "Professional Liability Insurance") [1](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite")
- Request actual limits, retentions, premium and applicable exclusions from each. [5](https://www.harperinsure.com/coverages/professional-liability "Professional Liability Insurance") [1](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite")
- Confirm whether At-Bay’s broker submission route works for you. [1](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite")

## At-Bay vs Harper Professional Liability (E&O) Insurance Compared

| Criteria | At-Bay Miscellaneous Professional Liability (MPL) Insurance | Harper Professional Liability Insurance |
| --- | --- | --- |
| Who It’s For | At-Bay says it provides primary MPL for businesses of all revenue sizes with limits up to $5 million, subject to state restrictions and eligibility requirements detailed in a separate MPL appetite guide. [1](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite") (Evidence: Company-reported; scope: Current MPL appetite paragraph; the linked appetite guide's specific eligibility requirements were not independently opened for this record..) | Harper targets consultants, agencies, tech firms and licensed professionals whose work product is advice, design or a decision, since general liability doesn't cover a client claiming that work caused a financial loss. [5](https://www.harperinsure.com/coverages/professional-liability "Professional Liability Insurance") (Evidence: Company-reported; scope: Professional liability page introduction and FAQ distinguishing it from general liability..) |
| How to Apply | At-Bay directs MPL submissions to underwriting by email or through automatic quotes on its Broker Platform, which At-Bay describes as a workflow of creating a quote, customizing limits and retentions, and binding the policy. [1](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite") [4](https://www.at-bay.com/brokers/platform/ "Broker Platform") (Evidence: Company-reported; scope: Current submission instructions and the general broker-platform workflow description; MPL-specific automation details were not separately confirmed..) | You request a quote online or by phone; if a client contract requires E&O, Harper says it places coverage matching that requirement and issues the certificate the same day. [5](https://www.harperinsure.com/coverages/professional-liability "Professional Liability Insurance") (Evidence: Company-reported; scope: Professional liability page quote form and FAQ 'My client contract requires E&O. What now?'..) |
| Coverage Features | At-Bay lists MPL coverage highlights including automatic coverage for acquired subsidiaries, claims-made-and-reported coverage, coverage for independent contractors, disciplinary-proceedings defense, a duty-to-defend contract, personal-injury coverage (including emotional distress), punitive damages where insurable, a professional-services definition written for each insured, and an 80/20 hammer clause. [1](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite") (Evidence: Company-reported; scope: Product-page coverage-highlights list; an 80/20 hammer clause is a settlement provision where the insurer pays 80% and the insured pays 20% of costs after the insured declines a recommended settlement. The issued policy and declarations control actual wording, limits and exclusions..) | Harper describes coverage for errors and omissions in the work itself, negligence allegations about professional judgment, and legal defense costs, with limits it says are matched to the client contracts that require the policy. [5](https://www.harperinsure.com/coverages/professional-liability "Professional Liability Insurance") [6](https://www.harperinsure.com/coverages/errors-and-omissions "Errors and Omissions Insurance") (Evidence: Company-reported; scope: Professional liability page's four coverage tiles; the E&O page adds that claims often surface a year or more after the work was delivered. The issued policy and its exclusions control actual scope..) |
| Role in This Line | At-Bay markets MPL as one of its own named insurance products, sold through its disclosed producer, At-Bay Insurance Services LLC, with the product page directed at "properly licensed insurance professionals" submitting business rather than at direct retail buyers. [1](https://www.at-bay.com/insurance/mpl/ "MPL Insurance: Coverage Highlights & Appetite") [2](https://www.at-bay.com/licenses/ "Licenses") (Evidence: Company-reported; scope: Current MPL product page and license disclosures; this describes the distribution channel, not who bears the underwriting risk..) | Harper places professional liability coverage as a broker, writing the policy around the applicant's actual services rather than underwriting it, and describes a specialist handling the placement. [5](https://www.harperinsure.com/coverages/professional-liability "Professional Liability Insurance") (Evidence: Company-reported; scope: Professional liability page introduction and 'Why Harper' section..)<br><br>Harper markets the identical policy under two catalogue entries, "Professional Liability" and "Errors and Omissions"; the E&O page states it is the same policy, just named what a given industry calls it. [6](https://www.harperinsure.com/coverages/errors-and-omissions "Errors and Omissions Insurance") [7](https://www.harperinsure.com/coverages "What We Cover") (Evidence: Company-reported; scope: Coverage directory listing plus the E&O page's own description; a naming convention Harper states about itself, not a distinction between two products..) |

## About At-Bay and Harper and Professional Liability (E&O) Insurance

- [At-Bay company profile](https://spot.insure/insurance-providers/at-bay) · [At-Bay customer reviews](https://spot.insure/insurance-providers/at-bay/reviews)
- [Harper company profile](https://spot.insure/insurance-providers/harper) · [Harper customer reviews](https://spot.insure/insurance-providers/harper/reviews)
- [What Is Professional Errors and Omissions (E&O) Insurance?](https://spot.insure/coverage/professional-errors-omissions)

## Related Pages for At-Bay vs Harper Professional Liability (E&O)

- [At-Bay vs Harper](https://spot.insure/compare/at-bay-vs-harper): all coverage lines, business roles, service and claims.
- [What Is Professional Errors and Omissions (E&O) Insurance?](https://spot.insure/coverage/professional-errors-omissions): Professional liability can help pay covered defense costs and losses when a client says your advice or service caused financial harm; check services and reporting terms.
- [At-Bay Professional Liability (E&O) Insurance](https://spot.insure/insurance-providers/at-bay/professional-errors-omissions)
- [Harper Professional Liability (E&O) Insurance](https://spot.insure/insurance-providers/harper/professional-errors-omissions)

## Sources for At-Bay vs Harper Professional Liability (E&O) Insurance

### Sources About At-Bay

1. [MPL Insurance: Coverage Highlights & Appetite](https://www.at-bay.com/insurance/mpl/). At-Bay; MPL Coverage Highlights list; MPL Appetite paragraph; Send us your submissions; "material on this page is intended for use solely by properly licensed insurance professionals". Accessed 2026-09-23.
2. [Licenses](https://www.at-bay.com/licenses/). At-Bay; Producer introduction; agency and surplus-lines footer naming At-Bay Insurance Services LLC. Accessed 2026-09-16.
3. [At-Bay Doubles Miscellaneous Professional Liability Appetite](https://www.at-bay.com/press_releases/at-bay-doubles-mpl/). At-Bay; September 28, 2023 release: final paragraph before Media Contacts. Accessed 2026-09-16.
4. [Broker Platform](https://www.at-bay.com/brokers/platform/). At-Bay; How it works: Create a quote, Customize your quote, Bind your policy, Manage renewals; FAQs. Accessed 2026-09-16.

### Sources About Harper

5. [Professional Liability Insurance](https://www.harperinsure.com/coverages/professional-liability). Harper; Know your coverage: What is Professional Liability insurance?; Errors & omissions, Negligence allegations, Legal defense, Contract-driven limits; Why Harper; FAQs on general liability vs. E&O, client E&O requirements, and pricing drivers. Accessed 2026-09-23.
6. [Errors and Omissions Insurance](https://www.harperinsure.com/coverages/errors-and-omissions). Harper; Page states the product is 'Same policy as professional liability, just what your industry calls it'; describes financial-loss claims from professional services and late-arriving claims. Accessed 2026-09-23.
7. [What We Cover](https://www.harperinsure.com/coverages). Harper; Coverage directory list including Errors and Omissions and Professional Liability as separate catalogue entries. Accessed 2026-09-23.

Updated 2026-09-25. Spot, a product of Tools for Enlightenment, publishes this research and works in the commercial insurance market. The comparison applies the same criteria to both providers. [Editorial policy](https://spot.insure/editorial-policy). To suggest a correction, [contact Spot](https://spot.insure/contact) with the page URL and supporting source.

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