Finding a qualified auditor or assurance professional can make the difference between confidence in your financial statements and costly compliance gaps. Whether you're a small business needing your first audit, a nonprofit required to have assurance work done, or a mid-market company seeking specialized expertise, knowing where to look and what to vet matters significantly. Here's how to identify and hire the right audit and assurance professional for your specific needs.
Understand Your Audit & Assurance Requirements First
Before searching, clarify exactly what type of work you need. An external financial statement audit (typically $5,000–$50,000+ depending on complexity) differs substantially from agreed-upon procedures, internal audits, or SOC 2 compliance reviews. Nonprofits often need audits to satisfy donors or grant requirements; public companies need audits for SEC filings; private companies may need them for loan covenants or investor requests.
Document your organization's revenue, complexity (multi-location, international operations, etc.), and any regulatory mandates. This clarity prevents wasted conversations with firms that don't offer what you actually need.
Check Professional Credentials & Licensing
Audit and assurance work should only be performed by CPAs or firms licensed in your state. Look for:
- CPA designation: Non-negotiable for external audits; verifies accounting education, exam passage, and ethics oversight
- State licensure: Confirm the firm or individual holds a current license (search your state's board of accountancy website)
- Audit-specific experience: Ask how many audits they've completed in your industry—a firm strong in manufacturing audits may lack healthcare or construction experience
- Peer review status: CPA firms typically undergo triennial peer reviews; ask to see the report or summary
If a professional can't quickly produce credentials, move on.
Search Through Multiple Channels
Directory platforms: Use the American Institute of CPAs (AICPA) Find a CPA tool or your state CPA society's directory. These filter by location and service type.
Local referrals: Ask your bank, legal counsel, or other trusted advisors for names of firms they've worked with. Referrals carry implicit quality signals.
Online marketplaces: Platforms like Mercoly let you compare local audit and assurance providers side-by-side, read verified credentials, and see client feedback—making it easier to shortlist candidates in your area.
Industry-specific associations: If you're in healthcare, nonprofits, or manufacturing, your industry body often maintains lists of firms experienced with your sector's audit requirements.
Evaluate Firm Size & Specialization
The "Big Four" (Deloitte, EY, KPMG, PwC) serve large enterprises; mid-tier firms (Grant Thornton, BDO, CliftonLarsonAllen) often suit mid-market companies; local or regional CPA firms typically serve small businesses and nonprofits. Larger isn't always better—a local firm with 15 audits of similar-sized nonprofits may deliver better value than a national firm billing at premium rates for minimal local attention.
Ask whether the firm has dedicated staff for your audit or if they'll pull in junior associates. For compliance audits under $10,000, a smaller firm may be appropriate; for complex audits or multi-location entities, mid-tier or larger firms often have necessary resources.
Request Proposals & Compare Quotes
Contact 3–5 qualified firms and request a written proposal. A solid proposal should include:
- Scope of work (what will be audited, what won't)
- Timeline (when fieldwork begins, when the report is due)
- Fee estimate with a range ($X–$Y based on assumptions)
- Team composition (who will lead, what's their experience)
- References from similar-sized clients in your industry
Fees vary dramatically by region and complexity, but expect to pay $8,000–$25,000 for a small business audit, $25,000–$75,000 for mid-market companies, and significantly more for complex engagements. The lowest quote isn't always the best; prioritize fit and expertise.
Vet References & Ask Direct Questions
Call at least two client references and ask:
- Did the firm complete the work on time and on budget?
- How responsive were they to questions during the audit?
- Did they identify any significant issues you should know about?
- Would you hire them again?
Frequently Asked Questions
Q: How long does an external audit typically take? Most audits take 4–12 weeks from start to finish, depending on complexity, but the intensive fieldwork phase usually runs 2–4 weeks on-site or remotely.
Q: Can I use the same firm for both audit and tax preparation? Yes, but some companies prefer separate firms to maintain audit independence; discuss this with your auditor, as rules vary by entity type and industry.
Q: What's the difference between an audit and a review or compilation? An audit provides the highest assurance level with extensive testing; a review offers moderate assurance with analytical procedures; a compilation simply organizes financial data with no assurance—each costs progressively less.
Start narrowing your search today by comparing qualified local audit professionals and requesting proposals tailored to your actual needs.