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

A CPA firm can use USI Insurance Services, which runs the AICPA program, underwritten by CNA, with engagement-letter templates included. Harper, a broker, targets consultants, agencies and tech firms.

USI's AICPA Professional Liability Program is underwritten by CNA for CPA firms specifically, while Harper writes a generalized E&O policy across professions without naming an insurer. ^4,¹

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

A Named Insurer, but Only for One Client Type

USI's own page states its AICPA Professional Liability Program is "underwritten by CNA," naming a carrier, but only for the CPA firms that qualify for the AICPA-endorsed program; USI's separate Business Services practice brokers E&O for other business types without naming an insurer there:

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. ⁴Company-reported. Direct quote from the AICPA program page; CNA underwrites only this named program, not USI's other professional-liability placements.

Harper's reviewed pages name pricing drivers such as services performed and revenue but do not disclose an issuing insurer or a limit figure for the generalized policy it places. ¹

Who Each Policy Is Built For

USI's AICPA program has been the endorsed provider for CPAs and their firms since 1994 and has offered accountant coverage since 1967, so its named-insurer advantage is specific to that one profession. ⁴ Harper instead writes its policy around the applicant's actual services for consultants, agencies, tech firms and other licensed professionals generally, rather than through a professional-association endorsement. ¹

What Comes With the Policy

USI says AICPA program firms get supportive claims handling plus exclusive risk-management resources, including engagement-letter templates, alongside the coverage itself. ⁴ Harper's differentiator is a described pre-purchase review: it says it reads a policy's exclusions line by line before a client buys, since two E&O policies with the same limit can respond differently to the same claim. ¹

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

If you're a CPA firm, confirm you qualify for USI's AICPA-endorsed, CNA-underwritten program rather than its general Business Services E&O placement. ⁴
Ask Harper for the issuing insurer and policy limit, since neither appears on its reviewed pages. ¹
Ask USI which risk-management resources apply outside the AICPA program if you're not a CPA firm. ⁶
Ask Harper which exclusions its review flagged for your specific services. ¹

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

Harper vs USI Insurance Services: Professional Liability (E&O) Insurance: documented features by provider

Criteria	Harper Professional Liability Insurance	AICPA Professional Liability Program (USI Affinity)
Who It’s For	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. ¹Company-reported. Professional liability page introduction and FAQ distinguishing it from general liability.	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. ⁴Company-reported. Program page description.
How to Apply	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. ¹Company-reported. Professional liability page quote form and FAQ 'My client contract requires E&O. What now?'.	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. ⁴Company-reported. Contact instructions on the AICPA program page.
Coverage Features	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. ^1,²Company-reported. 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.	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. ⁴Company-reported. Program page description; actual insuring agreements, exclusions and conditions are set by the issued CNA policy form.
Role in This Line	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. ¹Company-reported. Professional liability page introduction and 'Why Harper' section. 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. ^2,³Company-reported. Coverage directory listing plus the E&O page's own description; a naming convention Harper states about itself, not a distinction between two products.	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. ^4,⁶Company-reported. AICPA program page and Business Services practice page.
Risk 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. ¹Company-reported. Professional liability page 'We know this' section; a described review practice, not an independently verified outcome.	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. ⁴Company-reported. Program page description.