---
title: "Aon vs Harper: Professional Liability (E&O) Insurance"
description: "Aon tailors E&O structures to professional firms; Harper says it matches limits to client contracts and reviews exclusions line by line."
canonical: "https://spot.insure/compare/aon-vs-harper/professional-errors-omissions"
page-type: "line-comparison"
updated-at: "2026-09-30"
comparison-pair: "aon-vs-harper"
provider-a: "aon"
provider-b: "harper"
coverage-line: "professional-errors-omissions"
---

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

## Agent Guide

**What this page is:** Focused comparison of Aon 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 Aon versus Harper. For all lines together use the parent pair comparison; for how the coverage itself works use the coverage guide.

**Questions this page answers:**
- Aon vs Harper for Professional Liability (E&O) Insurance: how do they differ?
- Which is better for Professional Liability (E&O) Insurance, Aon or Harper?
- What does Aon or Harper publish about Professional Liability (E&O) Insurance (limits, eligibility, claims, add-ons)?
- What should I confirm in a quote for Professional Liability (E&O) Insurance from Aon or Harper?

**Key facts:**
- Line: Professional Liability (E&O) Insurance. Providers: Aon and Harper.
- Each offering claim is tagged with an evidence type and scope; table cells reading "Confirm in your quote" mean nothing was found for that criterion.
- Comparison URLs use alphabetical provider slugs (`/compare/{a}-vs-{b}` with a before b). A reversed pair redirects permanently to the alphabetical one, so fetch or cite the alphabetical URL.

**Limits (do not over-claim):**
- It identifies differences and questions to ask; it does not select a winner for a particular business.
- "Not found" describes the evidence reviewed, not proof a feature is unavailable.
- 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 in the Sources section; last updated 2026-09-30. Editorial policy: /editorial-policy.

**Related pages:**
- [Aon vs Harper](https://spot.insure/compare/aon-vs-harper) — parent: all coverage lines for this pair
- [Professional Liability (E&O) Insurance guide](https://spot.insure/coverage/professional-errors-omissions) — coverage explainer for this line
- [Aon profile](https://spot.insure/insurance-providers/aon) — provider profile (evidence)
- [Harper profile](https://spot.insure/insurance-providers/harper) — provider profile (evidence)
- [Aon vs Harper Commercial Property Insurance](https://spot.insure/compare/aon-vs-harper/commercial-property) — sibling comparison (other line, or other pair for this line)
- [Aon vs Harper Cyber Insurance](https://spot.insure/compare/aon-vs-harper/cyber) — sibling comparison (other line, or other pair for this line)
- [Aon vs Harper General Liability Insurance](https://spot.insure/compare/aon-vs-harper/general-liability) — sibling comparison (other line, or other pair for this line)
- [Aon vs Harper Workers’ Compensation Insurance](https://spot.insure/compare/aon-vs-harper/workers-compensation) — sibling comparison (other line, or other pair for this line)
- [AIG vs Aon Professional Liability (E&O) Insurance](https://spot.insure/compare/aig-vs-aon/professional-errors-omissions) — sibling comparison (other line, or other pair for this line)
- [AIG vs Harper Professional Liability (E&O) Insurance](https://spot.insure/compare/aig-vs-harper/professional-errors-omissions) — sibling comparison (other line, or other pair for this line)
- [Alliance Risk vs Aon Professional Liability (E&O) Insurance](https://spot.insure/compare/alliance-risk-vs-aon/professional-errors-omissions) — sibling comparison (other line, or other pair for this line)
- [Alliance Risk vs Harper Professional Liability (E&O) Insurance](https://spot.insure/compare/alliance-risk-vs-harper/professional-errors-omissions) — sibling comparison (other line, or other pair for this line)
- [Aon vs At-Bay Professional Liability (E&O) Insurance](https://spot.insure/compare/aon-vs-at-bay/professional-errors-omissions) — sibling comparison (other line, or other pair for this line)
- [Aon vs The Baldwin Group Professional Liability (E&O) Insurance](https://spot.insure/compare/aon-vs-baldwin/professional-errors-omissions) — sibling comparison (other line, or other pair for this line)

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

Aon tailors E&O structures to professional firms; Harper says it matches limits to client contracts and reviews exclusions line by line.

## Research Scope and Use

Use this comparison to evaluate Aon and Harper for Professional Liability (E&O) Insurance against the same documented criteria. It identifies differences and questions to confirm; it does not select a winner for a particular business. Offering claims are what each provider publishes about this line unless marked otherwise. “Not found” describes the evidence reviewed, not proof that a feature is unavailable. Confirm the insurer, policy wording, limits, retentions, exclusions and cost in an actual quote.

## Summary

Aon describes tailored professional-liability structures without form-level detail. Harper describes E&O for advice, design and professional judgment, with contract-matched limits and exclusion review. [3](https://www.aon.com/en/capabilities/risk-transfer/professional-services-practice "Professional Services Practice") [6](https://www.harperinsure.com/coverages/professional-liability "Professional Liability Insurance") [7](https://www.harperinsure.com/coverages/errors-and-omissions "Errors and Omissions Insurance")

## What Is Aon?

Aon’s U.S. Commercial Risk terms describe brokerage for certain insurance programs, while its Middle Market page describes a dedicated practice for mid-sized organizations across North America. The public materials reviewed do not identify the licensed producer or insurer for a particular placement. Ask which entity will produce each line and which insurer will issue the policy; request jurisdiction details for the proposed placement and ask how compensation and claim notice work for your account. [1](https://www.aon.com/en/about/leadership-and-governance/brokerage-terms-of-service-for-commercial-risk-solutions-us "Commercial Risk Solutions U.S. Brokerage Terms of Service") [2](https://www.aon.com/en/capabilities/middle-market-clients "Middle Market Clients")

[Aon profile](https://spot.insure/insurance-providers/aon)

## What Is Harper Insurance?

Harper suits hard-to-place businesses such as contractors, care providers, manufacturers and transportation firms; standard small businesses seeking direct quotes should compare online carriers. Its workers’ compensation service helps classify payroll for audits. [4](https://www.harperinsure.com/sms-terms "Text Messaging Terms and Conditions") [5](https://www.harperinsure.com/insurance-insights/harper-45m-funding-announcement "We're Announcing $47M to Build the Insurance Company Every Business Deserves")

[Harper profile](https://spot.insure/insurance-providers/harper)

## What Is Professional Errors and Omissions (E&O) Insurance?

Professional liability can help pay defense costs and covered losses when a client says your advice or service caused financial harm. If customers rely on your work, list every service you provide and check the claims-made reporting and prior-work terms. [9](https://www.tdi.texas.gov/commercial/pl-faq.html "FAQ: Professional liability insurance") [10](https://www.iii.org/article/professional-liability-insurance "Professional liability insurance") [11](https://www.sba.gov/counseling/launch-your-business/#business-insurance "Get business insurance") [12](https://www.hiscox.com/documents/pl-sample-policy-wording.pdf "Professional Liability – US Direct Errors and Omissions Insurance")

## Key Differences in Professional Liability (E&O) Insurance

### Coverage and Policy Design

Aon describes professional liability as a structure tailored to firms’ needs, while Harper targets consultants, agencies, technology firms and licensed professionals whose work is advice, design or a decision. Harper says its coverage addresses work errors, professional-judgment allegations and legal defense, with limits matched to client-contract requirements. If a contract specifies an E&O limit, Harper’s stated approach gives buyers a direct question to raise; ask Aon to map its proposed limit to the same contract. [3](https://www.aon.com/en/capabilities/risk-transfer/professional-services-practice "Professional Services Practice") [6](https://www.harperinsure.com/coverages/professional-liability "Professional Liability Insurance")

### Buying Route and Terms

Harper says it reads exclusions line by line because policies with the same limit can respond differently; Aon’s public overview does not describe an exclusion-review service. Harper offers online or phone quotes and says it can issue a certificate the same day when matching a client requirement. Aon describes advisor placement but gives no timing commitment. Neither overview names the issuing carrier or publishes standard limits. Confirm terms and insurer before relying on a certificate. [3](https://www.aon.com/en/capabilities/risk-transfer/professional-services-practice "Professional Services Practice") [6](https://www.harperinsure.com/coverages/professional-liability "Professional Liability Insurance")

## What to Confirm in Professional Liability (E&O) Insurance Quotes

- Ask Harper to show how each client-contract requirement maps to the insurer’s form and exclusions. [3](https://www.aon.com/en/capabilities/risk-transfer/professional-services-practice "Professional Services Practice") [6](https://www.harperinsure.com/coverages/professional-liability "Professional Liability Insurance")
- Ask Aon for a policy exclusion review, certificate timing and account-specific limit. [3](https://www.aon.com/en/capabilities/risk-transfer/professional-services-practice "Professional Services Practice") [6](https://www.harperinsure.com/coverages/professional-liability "Professional Liability Insurance")

## Offering Details

| Criteria | Aon Professional Liability / E&O brokerage and risk-advisory offering | Harper Professional Liability Insurance |
| --- | --- | --- |
| Role in This Line | Aon presents Professional Liability / E&O as a line its Professional Services Practice helps arrange or advise on for professional-service firms. Aon is describing a global brokerage and advisory service, not issuing the underlying policy. The producing legal entity and carrier for any particular placement are not named on this page. [3](https://www.aon.com/en/capabilities/risk-transfer/professional-services-practice "Professional Services Practice") (Evidence: Company-reported; scope: Aon’s global professional-services practice page. This establishes a marketed brokerage/advisory offering, not policy issuance or account-specific placement..) | 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. [6](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. [7](https://www.harperinsure.com/coverages/errors-and-omissions "Errors and Omissions Insurance") [8](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..) |
| Issuing Insurer | The reviewed practice page does not name the insurer or producing legal entity for a specific placement. Ask for both on the quote and binder. [3](https://www.aon.com/en/capabilities/risk-transfer/professional-services-practice "Professional Services Practice") (Evidence: Not found in reviewed sources; scope: Aon’s global practice page as reviewed 2026-09-30; no state-specific placement schedule or buyer quote was reviewed. This does not establish that Aon cannot arrange a placement..) | The reviewed pages name pricing drivers (services performed, revenue, contract size) but do not name the issuing insurer or publish specific limit, retention or premium figures for this line. [6](https://www.harperinsure.com/coverages/professional-liability "Professional Liability Insurance") [7](https://www.harperinsure.com/coverages/errors-and-omissions "Errors and Omissions Insurance") (Evidence: Not publicly disclosed; scope: Checked both the professional-liability and errors-and-omissions pages on 2026-09-23; neither names a carrier or a limit figure..) |
| Who It’s For | Aon identifies law, accounting and consulting firms as the audience for its global Professional Services Practice. That audience scope does not establish eligibility for every firm or other business. [3](https://www.aon.com/en/capabilities/risk-transfer/professional-services-practice "Professional Services Practice") (Evidence: Company-reported; scope: Audience described for Aon’s global professional-services practice. It does not establish U.S. state availability or underwriting eligibility for a placement..) | 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. [6](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..) |
| Coverage Features | Aon describes professional liability as addressing professional-services firms’ liability exposure and says it tailors coverage structures to a firm’s needs. It identifies E&O as a commonly used name for professional-liability insurance; actual policy terms are not stated. [3](https://www.aon.com/en/capabilities/risk-transfer/professional-services-practice "Professional Services Practice") (Evidence: Company-reported; scope: Aon’s marketing description of the brokerage/coverage area. The page is not the insurer’s policy form and does not establish an insured's entitlement to coverage..) | 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. [6](https://www.harperinsure.com/coverages/professional-liability "Professional Liability Insurance") [7](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..) |
| Limits and Retentions | The reviewed page does not state a buyer-specific limit, retention, deductible or other placement terms. Confirm these in the quote, bond or issued policy. [3](https://www.aon.com/en/capabilities/risk-transfer/professional-services-practice "Professional Services Practice") (Evidence: Not publicly disclosed; scope: Aon’s global practice page as reviewed 2026-09-30; no quote, bond form or issued policy was reviewed..) | Confirm in your quote. |
| Risk Services | Aon says its professional-services advisors use industry knowledge, insights, data and tools to support risk-management and human-capital decisions. This is a company-described advisory service, not a claim outcome or policy benefit. [3](https://www.aon.com/en/capabilities/risk-transfer/professional-services-practice "Professional Services Practice") (Evidence: Company-reported; scope: Company-reported advisory services on Aon’s global practice page; account-specific service scope is not stated..) | Harper says it reads a policy's exclusions line by line before a client buys, because two E&O policies with the same limit can respond very differently to the same claim. [6](https://www.harperinsure.com/coverages/professional-liability "Professional Liability Insurance") (Evidence: Company-reported; scope: Professional liability page 'We know this' section; a described review practice, not an independently verified outcome..) |
| How to Apply | Confirm in your quote. | 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. [6](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?'..) |

## Full Comparison

- [Aon vs Harper](https://spot.insure/compare/aon-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.
- [Aon vs Harper Commercial Property Insurance](https://spot.insure/compare/aon-vs-harper/commercial-property)
- [Aon vs Harper Cyber Insurance](https://spot.insure/compare/aon-vs-harper/cyber)
- [Aon vs Harper General Liability Insurance](https://spot.insure/compare/aon-vs-harper/general-liability)
- [Aon vs Harper Workers’ Compensation Insurance](https://spot.insure/compare/aon-vs-harper/workers-compensation)
- [AIG vs Aon Professional Liability (E&O) Insurance](https://spot.insure/compare/aig-vs-aon/professional-errors-omissions)
- [AIG vs Harper Professional Liability (E&O) Insurance](https://spot.insure/compare/aig-vs-harper/professional-errors-omissions)
- [Alliance Risk vs Aon Professional Liability (E&O) Insurance](https://spot.insure/compare/alliance-risk-vs-aon/professional-errors-omissions)
- [Alliance Risk vs Harper Professional Liability (E&O) Insurance](https://spot.insure/compare/alliance-risk-vs-harper/professional-errors-omissions)
- [Aon vs At-Bay Professional Liability (E&O) Insurance](https://spot.insure/compare/aon-vs-at-bay/professional-errors-omissions)
- [Aon vs The Baldwin Group Professional Liability (E&O) Insurance](https://spot.insure/compare/aon-vs-baldwin/professional-errors-omissions)

## Sources

### Aon

1. [Commercial Risk Solutions U.S. Brokerage Terms of Service](https://www.aon.com/en/about/leadership-and-governance/brokerage-terms-of-service-for-commercial-risk-solutions-us). Aon; Lines 120–127: certain-program broker-of-record scope, consultation, application assistance, client signature and bind instruction, and account administration; lines 140–147: variable and contingent compensation, potential placement incentive, and client request route; lines 206–213: no price guarantee and surplus-lines limitations; lines 229–231: client insurer-notice duty unless separately agreed.. Accessed 2026-09-29.
2. [Middle Market Clients](https://www.aon.com/en/capabilities/middle-market-clients). Aon; Lines 125–132: mid-sized organizations and middle-market framing; lines 165–173: dedicated practice and North America statement; lines 188–224: Commercial Risk capabilities. No numeric company-size cutoff or U.S.-only eligibility rule is stated on the reviewed page.. Accessed 2026-09-29.
3. [Professional Services Practice](https://www.aon.com/en/capabilities/risk-transfer/professional-services-practice). Aon; Named professional-services audiences and global advisory role, lines 125–128; line offerings and explanations lines 131–190; contact link lines 120–122. Global practice page; no U.S. state or account-specific placement schedule.. Accessed 2026-09-30.

### Harper

4. [Text Messaging Terms and Conditions](https://www.harperinsure.com/sms-terms). Harper Global Enterprises Inc.; Effective August 24, 2026; sections 1–3 (entity, consent and service messages), 5 (message costs), 9 (delivery) and 11 (coverage confirmation). Accessed 2026-09-15.
5. [We're Announcing $47M to Build the Insurance Company Every Business Deserves](https://www.harperinsure.com/insurance-insights/harper-45m-funding-announcement). Harper / Dakotah Rice; February 26, 2026 article: brokerage identity; AI-assisted submissions and follow-ups; 24–48-hour coverage statement; more than 165 underwriters; plans for additional direct appointments. Accessed 2026-09-15.
6. [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.
7. [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.
8. [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.

### Professional Liability (E&O) Insurance Guide

9. [FAQ: Professional liability insurance](https://www.tdi.texas.gov/commercial/pl-faq.html). Texas Department of Insurance; What’s professional liability coverage?; What types of damages…; What’s general liability insurance?; Do I need professional liability… if I have general liability…?; Is professional liability insurance required?; Can a client require…?; What’s the difference between occurrence policies and claims-made policies. Accessed 2026-09-16.
10. [Professional liability insurance](https://www.iii.org/article/professional-liability-insurance). Insurance Information Institute; Opening paragraphs (professional services/advice and E&O name); Claims not covered by general liability; What types of businesses need professional liability insurance?; What’s covered… and what’s not (claims-made versus occurrence, defense and judgments, non-financial/intentional limits, BOP/in-home exclusion). Accessed 2026-09-16.
11. [Get business insurance](https://www.sba.gov/counseling/launch-your-business/#business-insurance). U.S. Small Business Administration; Six common types of business insurance table. Accessed 2026-09-16.
12. [Professional Liability – US Direct Errors and Omissions Insurance](https://www.hiscox.com/documents/pl-sample-policy-wording.pdf). Hiscox Inc. specimen; About this Policy / Coverage for Claims Made Against You; I.A Insuring Agreement; I.B Defense; I.C Settlement; II.A Notice of Claims; II.C Optional Extended Reporting Period; III.A, III.K, III.M, III.R, III.S Exclusions; IV.A–B Limits and Deductible; VI.O Professional Services; VI.U Wrongful Act. Accessed 2026-09-16.

Updated 2026-09-30. 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.

## Aon Reviews

Review Score: 6.1 / 10 from 3 rated sources, equally weighted.

Public ratings for Aon are low: Trustpilot shows 1.2 out of 5 from 782 reviews, and BBB shows 1.6 from five. Aon is a global firm, so those pages mostly reflect other parts of the business, not large U.S. commercial accounts.

- J.D. Power: Aon study score 822 (out of 1000). Historical 2017 large-commercial-broker study; U.S. and Canada commercial insurance decision-makers at large organizations. J.D. Power reports 2,506 evaluations across the study, not Aon-specific responses; the Aon respondent count is not stated. Period: 2017 study; ranked 3rd among large commercial brokers; study-wide population 2,506, not Aon review count. Checked 2026-09-29. [Diversity of Offerings Becomes Key Differentiator for Large Commercial Insurers, JD Power Finds](https://www.jdpower.com/business/press-releases/jd-power-2017-large-commercial-insurance-study)
- Trustpilot: TrustScore 1.2 (out of 5); 782 reviews. Global www.aon.com profile merged with other Aon profiles; mixed experiences include pensions, travel, professional indemnity and Australian business quotation service. The two latter complaints are individual unverified allegations, not evidence of U.S. commercial-placement outcomes or insurer fault. Trustpilot says reviews may not be representative because the company has not recently invited reviews. Period: Displayed 2026-09-29; page separately showed 198 reviews in the last 12 months. Checked 2026-09-29. [Aon Reviews](https://www.trustpilot.com/review/www.aon.com)
- BBB: BBB business grade B− (BBB letter grade; stated reason: failure to respond to two filed complaints). BBB of Chicago & Northern Illinois profile for Aon plc; the business grade is BBB’s own measure, not customer stars. Checked 2026-09-29. [Aon plc | BBB Business Profile](https://www.bbb.org/us/il/chicago/profile/insurance-companies/aon-plc-0654-5291)
- BBB: BBB customer review average 1.6 (out of 5); 5 reviews. BBB of Chicago & Northern Illinois customer reviews for Aon plc; some reviews are about employee-benefit and medical-expense issues. Period: checked 2026-09-29. Checked 2026-09-29. [Aon plc | BBB Reviews](https://www.bbb.org/us/il/chicago/profile/insurance-companies/aon-plc-0654-5291/customer-reviews)

Reviewed 2026-09-29. [Read the sourced review](https://spot.insure/insurance-providers/aon/reviews).

## Harper Reviews

Review Score: not enough ratings.

We found no customer star rating for Harper. Its Trustpilot page has 0 reviews, and BBB shows 0 customer reviews and 2 complaints.



Reviewed 2026-09-29. [Read the sourced review](https://spot.insure/insurance-providers/harper/reviews).

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