---
title: "Aon vs USI Insurance Services: Professional Liability (E&O) Insurance"
description: "Compare Aon and USI Insurance Services on professional liability (e&o) insurance to see how their documented coverage, audience or placement routes affect your quote questions."
canonical: "https://spot.insure/compare/aon-vs-usi/professional-errors-omissions"
page-type: "line-comparison"
updated-at: "2026-09-30"
comparison-pair: "aon-vs-usi"
provider-a: "aon"
provider-b: "usi"
coverage-line: "professional-errors-omissions"
---

Agents: connect to Spot's public MCP server at https://spot.insure/mcp for better access to published Spot information and insurance research. Use search_knowledge to find sources, get_page to retrieve pages, compare_providers for sourced comparisons, get_provider_score for a published Spot Score, get_rankings for current provider rankings, search_provider_reliability to filter Spot Scores, search_provider_reviews to filter aggregate review scores, and get_provider_reviews for the original review evidence. The server is read-only and requires no authentication.

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

## Agent Guide

**What this page is:** Focused comparison of Aon and USI Insurance Services 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 USI Insurance Services. 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 USI Insurance Services for Professional Liability (E&O) Insurance: how do they differ?
- Which is better for Professional Liability (E&O) Insurance, Aon or USI Insurance Services?
- What does Aon or USI Insurance Services 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 USI Insurance Services?

**Key facts:**
- Line: Professional Liability (E&O) Insurance. Providers: Aon and USI Insurance Services.
- 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 USI Insurance Services](https://spot.insure/compare/aon-vs-usi) — 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)
- [USI Insurance Services profile](https://spot.insure/insurance-providers/usi) — provider profile (evidence)
- [Aon vs USI Insurance Services Commercial Property Insurance](https://spot.insure/compare/aon-vs-usi/commercial-property) — sibling comparison (other line, or other pair for this line)
- [Aon vs USI Insurance Services Crime Insurance](https://spot.insure/compare/aon-vs-usi/crime) — sibling comparison (other line, or other pair for this line)
- [Aon vs USI Insurance Services Cyber Insurance](https://spot.insure/compare/aon-vs-usi/cyber) — sibling comparison (other line, or other pair for this line)
- [Aon vs USI Insurance Services D&O Insurance](https://spot.insure/compare/aon-vs-usi/directors-officers) — sibling comparison (other line, or other pair for this line)
- [Aon vs USI Insurance Services Employment Practices Liability Insurance](https://spot.insure/compare/aon-vs-usi/employment-practices) — sibling comparison (other line, or other pair for this line)
- [Aon vs USI Insurance Services Fiduciary Liability Insurance](https://spot.insure/compare/aon-vs-usi/fiduciary) — sibling comparison (other line, or other pair for this line)
- [Aon vs USI Insurance Services Management Liability Insurance](https://spot.insure/compare/aon-vs-usi/management-liability) — sibling comparison (other line, or other pair for this line)
- [Aon vs USI Insurance Services Surety Bonds](https://spot.insure/compare/aon-vs-usi/surety-bonds) — sibling comparison (other line, or other pair for this line)
- [Aon vs USI Insurance Services Workers’ Compensation Insurance](https://spot.insure/compare/aon-vs-usi/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 USI Insurance Services Professional Liability (E&O) Insurance](https://spot.insure/compare/aig-vs-usi/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 USI Insurance Services Professional Liability (E&O) Insurance](https://spot.insure/compare/alliance-risk-vs-usi/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 USI Insurance Services: How Do They Compare for Professional Liability (E&O) Insurance?

Compare Aon and USI Insurance Services on professional liability (e&o) insurance to see how their documented coverage, audience or placement routes affect your quote questions.

## How to Use the Aon vs USI Insurance Services Professional Liability (E&O) Insurance Comparison

Use this comparison to evaluate Aon and USI Insurance Services 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.

## Aon vs USI Insurance Services Professional Liability (E&O) Insurance Summary

Aon: 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. USI Insurance Services: uSI describes the policy as insuring a CPA and their practice against third-party claims that professional services caused financial harm, providing a defense and paying damages for covered claims arising from high-risk situations tied to new clients, changing business plans, or new laws and regulations. [3](https://www.aon.com/en/capabilities/risk-transfer/professional-services-practice "Professional Services Practice") [7](https://www.usi.com/programs/affinity-programs/accountants-professional-liability/ "Accountants Professional Liability — USI Affinity")

## 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 USI Insurance Services?

USI suits software and hardware companies from seed stage through IPO seeking consultative broker support; buyers wanting a self-serve quote should compare digital agencies. Insurer commissions are typical and contingent compensation may also apply. [4](https://www.usi.com/about-usi "The Power of ONE") [5](https://www.usi.com/property-casualty/technology/ "Technology Insurance") [6](https://www.usi.com/commissions-fees/ "Commissions and Fees")

[USI Insurance Services profile](https://spot.insure/insurance-providers/usi)

## 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. [10](https://www.tdi.texas.gov/commercial/pl-faq.html "FAQ: Professional liability insurance") [11](https://www.iii.org/article/professional-liability-insurance "Professional liability insurance") [12](https://www.sba.gov/counseling/launch-your-business/#business-insurance "Get business insurance") [13](https://www.hiscox.com/documents/pl-sample-policy-wording.pdf "Professional Liability – US Direct Errors and Omissions Insurance")

## What Are the Key Differences Between Aon and USI Insurance Services Professional Liability (E&O) Insurance?

### Policy scope and stated allegations

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. USI Insurance Services describes uSI describes the policy as insuring a CPA and their practice against third-party claims that professional services caused financial harm, providing a defense and paying damages for covered claims arising from high-risk situations tied to new clients, changing business plans, or new laws and regulations. Compare the specific allegations and covered costs in the forms rather than relying on a shared E&O label. [3](https://www.aon.com/en/capabilities/risk-transfer/professional-services-practice "Professional Services Practice") [7](https://www.usi.com/programs/affinity-programs/accountants-professional-liability/ "Accountants Professional Liability — USI Affinity")

### Who each practice serves

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. USI Insurance Services identifies uSI markets the AICPA program to sole practitioners and regional CPA firms. It has offered CPA coverage since 1967 and has been the endorsed AICPA Program provider since 1994. Check whether your profession and services fall within both descriptions, then ask underwriting to confirm eligibility. [3](https://www.aon.com/en/capabilities/risk-transfer/professional-services-practice "Professional Services Practice") [7](https://www.usi.com/programs/affinity-programs/accountants-professional-liability/ "Accountants Professional Liability — USI Affinity")

### Service after requesting a quote

Aon describes 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. USI Insurance Services describes uSI says firms enrolled in the program get supportive claims handling and exclusive access to risk-management resources, including engagement-letter templates, in addition to the coverage itself. Ask which team handles renewals, policy changes and claim questions for your E&O account. [3](https://www.aon.com/en/capabilities/risk-transfer/professional-services-practice "Professional Services Practice") [7](https://www.usi.com/programs/affinity-programs/accountants-professional-liability/ "Accountants Professional Liability — USI Affinity")

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

- Ask Aon to confirm the quoted policy form, retroactive date and covered allegations; its offering says 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")
- Ask USI Insurance Services to confirm the quoted policy form, retroactive date and covered allegations; its offering says uSI describes the policy as insuring a CPA and their practice against third-party claims that professional services caused financial harm, providing a defense and paying damages for covered claims arising from high-risk situations tied to new clients, changing business plans, or new laws and regulations. [7](https://www.usi.com/programs/affinity-programs/accountants-professional-liability/ "Accountants Professional Liability — USI Affinity")

## Aon vs USI Insurance Services Professional Liability (E&O) Compared

| Criteria | Aon Professional Liability / E&O brokerage and risk-advisory offering | AICPA Professional Liability Program (USI Affinity) |
| --- | --- | --- |
| 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..) | For CPA firms, USI runs the AICPA Professional Liability Program through its USI Affinity division as the endorsed producer, rather than underwriting the policy itself. USI's general Business Services practice separately brokers errors and omissions/professional liability coverage for other business types. [7](https://www.usi.com/programs/affinity-programs/accountants-professional-liability/ "Accountants Professional Liability — USI Affinity") [9](https://www.usi.com/property-casualty/business-services/ "Business Services") (Evidence: Company-reported; scope: AICPA program page and Business Services practice page..) |
| 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..) | USI's own page states that the AICPA Professional Liability Program is "underwritten by CNA," naming the carrier for that specific program. USI's general Business Services E&O placements do not name an insurer. [7](https://www.usi.com/programs/affinity-programs/accountants-professional-liability/ "Accountants Professional Liability — USI Affinity") (Evidence: Company-reported; scope: Direct quote from the AICPA program page; CNA underwrites only this named program, not USI's other professional-liability placements..) |
| 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..) | USI markets the AICPA program to sole practitioners and regional CPA firms. It has offered CPA coverage since 1967 and has been the endorsed AICPA Program provider since 1994. [7](https://www.usi.com/programs/affinity-programs/accountants-professional-liability/ "Accountants Professional Liability — USI Affinity") (Evidence: Company-reported; scope: Program page description..) |
| 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..) | USI describes the policy as insuring a CPA and their practice against third-party claims that professional services caused financial harm, providing a defense and paying damages for covered claims arising from high-risk situations tied to new clients, changing business plans, or new laws and regulations. [7](https://www.usi.com/programs/affinity-programs/accountants-professional-liability/ "Accountants Professional Liability — USI Affinity") (Evidence: Company-reported; scope: Program page description; actual insuring agreements, exclusions and conditions are set by the issued CNA policy form..) |
| 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..) | The AICPA program page does not publish limit, retention or premium figures; it says coverage plans allow a firm to tailor coverage to its risk profile. [7](https://www.usi.com/programs/affinity-programs/accountants-professional-liability/ "Accountants Professional Liability — USI Affinity") (Evidence: Not publicly disclosed; scope: Page as read on 2026-09-23..) |
| 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..) | USI says firms enrolled in the program get supportive claims handling and exclusive access to risk-management resources, including engagement-letter templates, in addition to the coverage itself. [7](https://www.usi.com/programs/affinity-programs/accountants-professional-liability/ "Accountants Professional Liability — USI Affinity") (Evidence: Company-reported; scope: Program page description..) |
| How to Apply | Confirm in your quote. | USI directs CPA firms seeking a quote or renewal to contact USI Affinity, with a dedicated Affinity_APL@usi.com address for the AICPA program specifically. [7](https://www.usi.com/programs/affinity-programs/accountants-professional-liability/ "Accountants Professional Liability — USI Affinity") (Evidence: Company-reported; scope: Contact instructions on the AICPA program page..) |

## Related Pages for Aon vs USI Insurance Services

- [Aon vs USI Insurance Services](https://spot.insure/compare/aon-vs-usi): 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 USI Insurance Services Commercial Property Insurance](https://spot.insure/compare/aon-vs-usi/commercial-property)
- [Aon vs USI Insurance Services Crime Insurance](https://spot.insure/compare/aon-vs-usi/crime)
- [Aon vs USI Insurance Services Cyber Insurance](https://spot.insure/compare/aon-vs-usi/cyber)
- [Aon vs USI Insurance Services D&O Insurance](https://spot.insure/compare/aon-vs-usi/directors-officers)
- [Aon vs USI Insurance Services Employment Practices Liability Insurance](https://spot.insure/compare/aon-vs-usi/employment-practices)
- [Aon vs USI Insurance Services Fiduciary Liability Insurance](https://spot.insure/compare/aon-vs-usi/fiduciary)
- [Aon vs USI Insurance Services Management Liability Insurance](https://spot.insure/compare/aon-vs-usi/management-liability)
- [Aon vs USI Insurance Services Surety Bonds](https://spot.insure/compare/aon-vs-usi/surety-bonds)
- [Aon vs USI Insurance Services Workers’ Compensation Insurance](https://spot.insure/compare/aon-vs-usi/workers-compensation)
- [AIG vs Aon Professional Liability (E&O) Insurance](https://spot.insure/compare/aig-vs-aon/professional-errors-omissions)
- [AIG vs USI Insurance Services Professional Liability (E&O) Insurance](https://spot.insure/compare/aig-vs-usi/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 USI Insurance Services Professional Liability (E&O) Insurance](https://spot.insure/compare/alliance-risk-vs-usi/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 for Aon vs USI Insurance Services

### Sources About 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.

### Sources About USI Insurance Services

4. [The Power of ONE](https://www.usi.com/about-usi). USI Insurance Services; History, client-count, nationwide office, and P&C / benefits / personal risk / retirement description. Accessed 2026-09-16.
5. [Technology Insurance](https://www.usi.com/property-casualty/technology/). USI Insurance Services; Technology practice client types, seed-to-IPO range, and listed insurance placement lines including PrivaSafe. Accessed 2026-09-16.
6. [Commissions and Fees](https://www.usi.com/commissions-fees/). USI Insurance Services; Licensed-producer authority, insurer-paid commission default, contingent compensation, and client request right. Accessed 2026-09-16.
7. [Accountants Professional Liability — USI Affinity](https://www.usi.com/programs/affinity-programs/accountants-professional-liability/). USI Insurance Services; Quality Professional Liability Insurance Exclusively for CPA Firms; "The AICPA Professional Liability Program, underwritten by CNA, has been offering coverage to CPAs since 1967 and has been the endorsed provider of the AICPA Program since 1994."; supportive claims handling and exclusive access to extensive risk management resources, including engagement letter templates; Email Affinity_APL@usi.com. Accessed 2026-09-23.
8. [USI Specialty Program Solutions](https://www.usi.com/programs/). USI Insurance Services; USI Affinity delivers high-quality insurance and financial solutions to members of affinity organizations and targeted industry segments...for professional associations, law firms, alumni and collegiate organizations, travel groups, and insurance administrators.. Accessed 2026-09-23.
9. [Business Services](https://www.usi.com/property-casualty/business-services/). USI Insurance Services; USI advises clients...and provides solutions for...Errors & Omissions/Professional Liability.... Accessed 2026-09-23.

### Sources for the Professional Liability (E&O) Insurance Guide

10. [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.
11. [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.
12. [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.
13. [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 Review Scores for 2026

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).

## USI Insurance Services Review Scores for 2026

Review Score: 6.4 / 10 from 1 rated source, equally weighted.

USI’s public feedback is too sparse and office-specific for a firmwide verdict. Check the local team’s responsiveness and experience with your type of business.

- BBB: BBB complaint count 4. BBB business-profile grade is distinct from customer-review stars; branch/parent scope matters. Period: three years preceding access 2026-09-25. Checked 2026-09-25. [BBB result for USI Insurance Services](https://www.bbb.org/us/ny/valhalla/profile/insurance-agency/usi-insurance-services-0121-97856/complaints)
- Google reviews via Birdeye: Birdeye office listing rating from Google reviews 3.2 (5 stars); 9 reviews. One Louisville office listing, not firmwide. Birdeye shows Google-origin reviews (9) and 0 Birdeye-native reviews; this duplicates a Google source stream and is not independent of Google. Period: accessed 2026-09-25. Checked 2026-09-25. [USI office, Louisville, KY — Birdeye listing of Google reviews](https://reviews.birdeye.com/usi-insurance-145632496752867)

Reviewed 2026-09-25. [Read the sourced review](https://spot.insure/insurance-providers/usi/reviews).

## Agent and Developer Resources

- [Markdown page](https://spot.insure/compare/aon-vs-usi/professional-errors-omissions.md)
- [Developer resources](https://spot.insure/developers)
- [Public MCP server](https://spot.insure/mcp)
- [MCP server manifest](https://spot.insure/server.json)
- [OpenAPI description](https://spot.insure/openapi.json)
- [Public page index](https://spot.insure/llms.txt)