Public companies cannot choose an external auditor based solely on price or technical experience. Before appointment, they must consider whether the accounting firm is independent under applicable Public Company Accounting Oversight Board (PCAOB) and Securities and Exchange Commission (SEC) requirements. A relationship or service that compromises independence can disrupt an audit even when the underlying financial records are accurate.
PCAOB independence rules help protect investors by requiring registered public accounting firms and relevant professionals to remain objective. They cover financial and business relationships, fee arrangements, tax services, and communications with audit committees. This guide explains what public companies must check before engaging independent auditors, and answers the important question: can you do tax services for a company you audit?
What Are PCAOB Independence Rules?
PCAOB independence rules are professional requirements that protect the objectivity of auditors performing engagements subject to PCAOB standards. They operate alongside SEC Regulation S-X, Rule 2-01, and other applicable standards.
Independence in fact means the auditor makes judgments without improper influence. Independence in appearance means avoiding situations that would cause a reasonable investor, aware of the relevant facts, to question the auditor’s impartiality.
An accounting firm can be highly experienced yet unable to perform a particular audit if it has a prohibited financial interest, takes on management functions, or must audit work that it prepared itself. For background on the overall process, see MBP Global’s PCAOB audit guide.
Why Independence Matters Before Hiring an Auditor
SEC compliance and filing reliability
An independence violation may call into question whether an audit report satisfies applicable SEC reporting requirements. Depending on the facts, the company may need additional work, a replacement auditor, or other corrective action. This can be especially disruptive when annual or registration statement deadlines are approaching.
Investor confidence
Shareholders, lenders, and other stakeholders rely on audited statements as an objective source of financial information. A compromised relationship can undermine trust even without a proven misstatement.
Time and cost
Late independence reviews can require management to revisit service contracts, historical relationships, and reporting periods. Addressing potential conflicts before appointment is typically more efficient. Read What Is an SEC Audit? for the broader SEC reporting context.
Key PCAOB Independence Rules
Rule 3520: Auditor Independence
PCAOB Rule 3520 requires a registered accounting firm and relevant associated persons to be independent of an audit client throughout the audit and professional engagement period. The rule also requires compliance with applicable SEC independence criteria. Public companies should request a clear assessment covering the firm, relevant affiliates, and personnel, rather than relying only on a general claim of independence.
Rule 3521: Contingent Fees
Rule 3521 addresses contingent fees and commissions involving audit clients. A fee tied to achieving a particular result may give the firm a conflicting incentive. Review compensation terms for audit-related and additional services, including tax engagements. Ordinary fixed-fee arrangements should still be examined for other independence issues.
Rule 3522: Tax Transactions
Rule 3522 restricts certain tax services involving confidential transactions and specified aggressive tax positions, including applicable listed transactions. A tax strategy that would produce a conflict cannot be made acceptable simply by labeling it advisory work. Proposed engagements involving complex structures or unusual tax positions warrant careful review.
Rule 3523: Tax Services for Individuals in Financial Reporting Oversight Roles
Rule 3523 generally prohibits specified personal tax services for people in financial reporting oversight roles at an issuer audit client, or their immediate family members, during the professional engagement period. Covered roles can include senior executives with financial reporting responsibility. Limited exceptions exist, so the people, circumstances, and timing should be assessed closely.
Rule 3524: Audit Committee Pre-Approval of Certain Tax Services
For permissible tax services to an issuer audit client, Rule 3524 requires written information about the scope, fee structure, and relevant arrangements, as well as a discussion of the potential effect on independence and documentation of that discussion. Required audit committee pre-approval does not override a substantive prohibition.
Rule 3525: Certain Non-Audit Services Related to Internal Control
Where permissible non-audit services relate to internal control over financial reporting, Rule 3525 requires written descriptions and audit committee discussion and documentation before pre-approval. This does not permit an external auditor to assume management functions or provide otherwise prohibited internal audit outsourcing. See the SOX compliance checklist.
Rule 3526: Independence Communications With Audit Committees
Rule 3526 calls for written disclosures and discussion of relationships reasonably thought to bear on independence before an initial engagement and recurring communications for ongoing engagements, including at least annual written affirmation. Audit committees should use these communications in their continuing oversight, not treat them as a mere signature exercise.
Can You Do Tax Services for a Company You Audit?
Yes, certain tax services may be permitted for a public-company audit client, provided they comply with SEC and PCAOB restrictions and receive required audit committee pre-approval. Permission depends on the nature of the work, who receives it, the fee arrangement, and whether it creates a management or self-review threat.
Tax services that may be permissible
· Preparation of some federal and state tax returns and routine tax compliance work.
· Certain tax planning advice that does not involve prohibited transactions or conflicts.
· Assistance interpreting tax regulations and selected international compliance requirements.
These examples are not blanket approvals. The specific scope must be evaluated before the engagement begins. For complementary context, see Corporate Tax Strategy, Compliance & Assurance Services.
Tax services that may impair independence
· Specified personal tax services to executives in financial reporting oversight roles or their immediate families.
· Services relating to prohibited tax transactions.
· Certain contingent-fee tax arrangements.
· Tax assignments that require the auditor to make management decisions or audit its own work in prohibited circumstances.
A key distinction is that preparing a tax return is not automatically the same as preparing a material income-tax provision recorded in audited financial statements. The latter may raise different self-review and management concerns. Read Comprehensive Tax Risk Management & Audit Services.
Which Non-Audit Services Are Restricted?
SEC Rule 2-01(c)(4), which works alongside PCAOB independence rules, restricts ten categories of non-audit services: bookkeeping, financial information system design and implementation, appraisal or valuation, actuarial services, internal audit outsourcing, management functions, human resources, broker-dealer and investment activities, legal services, and expert services unrelated to the audit. Specific conditions or narrow exceptions may apply within some categories.
For example, an auditor generally should not design a significant financial reporting system and then audit the information it produces. Nor may it manage the client's finance team while remaining its independent external auditor. The relevant question is the actual activity and its effect on independence, not merely the service label. See Internal Audit Services: Building a Compliance Foundation.
PCAOB Rules vs. SEC Auditor Independence Rules
The SEC establishes independence criteria for accountants involved in relevant SEC filings, including Regulation S-X, Rule 2-01. The PCAOB establishes additional ethics, independence, and communication standards for registered accounting firms, subject to SEC oversight. These are complementary, not alternative, regimes.
PCAOB Rule 3520 expressly ties independence to applicable SEC criteria. Thus, passing one firm's internal PCAOB checklist does not excuse a prohibited SEC financial, employment, business, or service relationship. Both sets of requirements must be considered in the circumstances of the engagement.
Public Company Auditor Selection Checklist
1. Confirm PCAOB registration and relevant experience
Verify the accounting firm's registration through official PCAOB resources and evaluate whether it has experience with your industry and reporting situation. Registration alone is not a finding of independence for your engagement.
2. Review financial and business relationships
Ask about prohibited investments, loans, business arrangements, affiliates, and relevant relationships involving audit personnel.
3. Inventory prior and existing services
Identify bookkeeping, financial reporting support, valuation, tax consulting, internal audit outsourcing, and systems implementation performed during relevant periods. IPO candidates should pay particular attention to historical services covering financial statements included in SEC filings.
4. Evaluate executive and employment relationships
Consider applicable restrictions on employment and family relationships, including cooling-off requirements in relevant situations.
5. Obtain audit committee review and pre-approval
The audit committee should evaluate the appointment and pre-approve permitted audit and non-audit engagements as required. Approval cannot convert an otherwise prohibited service into a permissible one.
6. Document independence communications
Request the required Rule 3526 disclosures and discuss each material relationship and potential effect.
7. Monitor independence after appointment
New subsidiaries, acquisitions, personnel moves, investments, and additional services can change the assessment mid-engagement.
Questions to Ask Independent Auditors
1. Is your firm registered with the PCAOB, and what comparable public-company audits has it performed?
2. Have you assessed independence under both SEC and PCAOB requirements for every relevant reporting period?
3. Do your firm, affiliates, or covered personnel have financial, employment, or business relationships with us?
4. Have you performed services that could require you to audit your own work?
5. What tax compliance and planning services, if any, can you perform without impairing independence?
6. How do you screen fees and service contracts for prohibited arrangements?
7. What written disclosures and audit committee approvals will you provide?
8. How will acquisitions, international operations, or restructuring affect your independence review?
These questions also complement practical financial statement audit preparation. See Audit and Assurance Services.
Common Independence Mistakes to Avoid
Assuming a tax engagement is automatically allowable
Routine tax compliance may be permissible, but service details, beneficiaries, compensation, and pre-approval still matter.
Relying on audit committee approval to override a prohibition
Pre-approval is required for many allowable services but does not legalize prohibited work.
Ignoring affiliates and historical engagements
The relationships and work of certain affiliates, covered personnel, and previous engagement periods can be relevant, especially in multinational groups.
Waiting until just before the filing date
Independence issues identified late can create avoidable disruption. Build assessments into vendor onboarding, auditor selection, and recurring oversight.
IPO, SPAC, and Growth-Stage Considerations
IPO-stage businesses may have used one provider for accounting, valuation, and advisory work before deciding to go public. Some of these historical assignments can create independence concerns for financial statements included in SEC registration documents. Companies should review the relevant periods early.
SPAC and de-SPAC transactions can involve multiple entities and legacy accounting firms. Review relationships involving the target, SPAC, and relevant affiliates as applicable. The SPAC and IPO Audit Readiness Guide offers additional questions for sponsors.
Growing public companies should revisit independence as subsidiaries are acquired or as reporting obligations and professional service needs change.
How MBP Global LLP Can Help
MBP Global LLP provides financial statement audit and assurance services for public and private businesses, including companies navigating SEC-related financial reporting requirements. Businesses comparing firms should evaluate relevant experience, engagement oversight, independence procedures, and service scope before appointment.
Any additional tax or advisory work must be assessed against the applicable independence restrictions for that particular audit client. Learn more in MBP Global's Audit and Assurance Services.
Frequently Asked Questions
What is PCAOB Rule 3520?
It requires registered public accounting firms and applicable associated persons to be independent of an audit client during the audit and professional engagement period, including under applicable SEC criteria.
Can an auditor prepare a company's tax returns?
Some tax return preparation may be permissible, with the necessary independence assessment and audit committee pre-approval. Tax engagements cannot involve prohibited transactions, personal services, fees, or self-review and management conflicts.
Does audit committee pre-approval make any service permissible?
No. Approval is required for specified permissible services; it does not override substantive prohibitions.
Is PCAOB registration proof of independence?
No. Registration and independence are separate determinations. The facts of the individual engagement control.
How often should independence be reviewed?
Before accepting the engagement and continually as circumstances change. Rule 3526 also specifies communications at least annually for continuing engagements.
What happens after an independence violation?
Depending on the facts, the company may face questions about its SEC audit report, corrective procedures, additional fees, changed auditors, or delays. The firm may face regulatory scrutiny.
Final Thoughts
PCAOB independence rules are not merely technical requirements for the accounting firm. They should be considered by CFOs, audit committees, and finance leaders before an auditor is selected and throughout the relationship. Reviewing prior services, financial relationships, tax engagements, fee arrangements, and written independence communications early can reduce reporting risks.
For assistance with a public-company audit, contact MBP Global LLP to discuss engagement requirements and next steps.
*Disclaimer: This article is educational, not legal or engagement-specific professional advice. Applicability depends on the facts, entities, services, and relevant periods.*
