Aon vs Harper: Professional Liability / E&O Insurance

When a client contract demands E&O, Harper says it matches that requirement and issues the certificate the same day; Aon is a global brokerage and advisory practice for law, accounting and consulting firms.

Kearny Risk organizes these comparisons for firms whose advice, content or technology creates professional exposures.Research updated 2026-09-30

What Are the Key Differences Between Aon and Harper 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. [1] [3]

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. [1] [3]

What Should You Confirm in Aon and Harper Professional Liability (E&O) Insurance Quotes?

  • Ask Harper to show how each client-contract requirement maps to the insurer’s form and exclusions. [1] [3]
  • Ask Aon for a policy exclusion review, certificate timing and account-specific limit. [1] [3]

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.

Sources reviewed

  1. 01
    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

  2. 02
    Errors and Omissions Insurance

    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

  3. 03
    Professional Liability Insurance

    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

  4. 04
    What We Cover

    Harper · Coverage directory list including Errors and Omissions and Professional Liability as separate catalogue entries · accessed 2026-09-23

  5. 05
    Professional Liability – US Direct Errors and Omissions Insurance

    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

  6. 06
    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

  7. 07
    FAQ: Professional liability insurance

    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

  8. 08
    Get business insurance

    U.S. Small Business Administration · Six common types of business insurance table · accessed 2026-09-16

Areas of coverage

Aon

  • role: 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. Aon’s global professional-services practice page. This establishes a marketed brokerage/advisory offering, not policy issuance or account-specific placement.company-reportedSource ↗
  • eligibility: 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. Audience described for Aon’s global professional-services practice. It does not establish U.S. state availability or underwriting eligibility for a placement.company-reportedSource ↗
  • coverage: 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. 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.company-reportedSource ↗
  • 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. Company-reported advisory services on Aon’s global practice page; account-specific service scope is not stated.company-reportedSource ↗
  • 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. 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.not-foundSource ↗
  • limits: 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. Aon’s global practice page as reviewed 2026-09-30; no quote, bond form or issued policy was reviewed.not-disclosedSource ↗

Harper

  • role: 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. Professional liability page introduction and 'Why Harper' section.company-reportedSource ↗
  • role: 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. Coverage directory listing plus the E&O page's own description; a naming convention Harper states about itself, not a distinction between two products.company-reportedSource ↗Source ↗
  • eligibility: 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. Professional liability page introduction and FAQ distinguishing it from general liability.company-reportedSource ↗
  • 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. 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.company-reportedSource ↗Source ↗
  • services: 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. Professional liability page 'We know this' section; a described review practice, not an independently verified outcome.company-reportedSource ↗
  • application: 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. Professional liability page quote form and FAQ 'My client contract requires E&O. What now?'.company-reportedSource ↗
  • insurer: 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. Checked both the professional-liability and errors-and-omissions pages on 2026-09-23; neither names a carrier or a limit figure.not-disclosedSource ↗Source ↗

Ask Kearny Risk to help relate this comparison to your services and contracts.

Contact Kearny Risk