Key Takeaways

  • Practitioners must exercise due diligence in preparing, approving, and filing documents.
  • Due diligence applies to all communications with the IRS and representations to clients.
  • May rely on client-provided information in good faith, but must make reasonable inquiries.
  • Cannot ignore obvious red flags or inconsistencies.
  • Failure to exercise due diligence can lead to OPR disciplinary action.
  • Technological competency is part of due diligence.
Last updated: January 2026

Due Diligence (Section 10.22): The Foundation of Practice

Why This Matters for the Exam

Due diligence is the foundational standard for all practitioner conduct under Circular 230. It applies to everything you do before the IRS—not just return preparation. The exam tests whether you understand when due diligence applies, what it requires, and when you can rely on client information.

Exam Note: For the May 2025 - February 2026 testing window, you are tested on Circular 230 as in effect through December 31, 2024 (Tax Year 2024).

Expect at least 3-4 questions on due diligence requirements.

What Is Due Diligence?

Due diligence means exercising reasonable care and competence in all professional activities. Under Circular 230 Section 10.22, practitioners must exercise due diligence in:

ActivityDescription
Preparing documentsTax returns, claims, submissions to IRS
Approving documentsReviewing and signing off on filings
Filing documentsSubmitting to the IRS
Determining correctnessVerifying accuracy of information
Oral representationsVerbal statements to IRS or clients
Written representationsLetters, memos, advice to clients

The Standard of Care

Due diligence does not require perfection. The standard is:

  • Reasonable care: Take steps a competent practitioner would take.
  • Reasonable inquiry: Ask questions when something appears incomplete or incorrect.
  • Good faith: Act honestly and without intent to deceive.

Key Point: You need not be ultimately correct—but you must have exercised reasonable care in reaching your conclusions.

Reliance on Client Information

Practitioners may rely on information provided by clients, but with limits:

When You Can RelyWhen You Cannot Rely
Information appears complete and correctInformation is obviously incomplete
Client has no history of providing false infoRed flags suggest information is false
No reason to doubt the informationInconsistencies with other known facts
You made reasonable inquiriesYou failed to ask obvious questions

The "Red Flag" Test: If something doesn't look right, you have a duty to inquire further. Ignoring obvious problems is a due diligence failure.

Examples of Due Diligence Failures

ScenarioDue Diligence Failure?
Claiming deduction without any documentation✅ Yes
Accepting client's verbal estimate without verification✅ Yes (for material items)
Filing return with obvious math errors✅ Yes
Not asking about foreign accounts despite large wire transfers✅ Yes
Accepting documented expenses at face value❌ No (reasonable reliance)

Technological Competency

Modern practice requires technological competency as part of due diligence. Practitioners must:

  • Understand technology used in tax practice (software, e-file, portals).
  • Protect client data from cybersecurity threats.
  • Stay current with IRS electronic systems and requirements.

Consequences of Due Diligence Failure

ConsequenceDescription
OPR ReferralOffice of Professional Responsibility investigation
CensurePublic reprimand
SuspensionTemporary loss of practice rights
DisbarmentPermanent loss of practice rights
IRC §6694 PenaltiesCivil preparer penalties

Real-World Scenario

Scenario: A client provides you with a list of business expenses totaling $50,000. The list has no receipts or documentation. The client says, "Just trust me."

  • Due Diligence Failure? Yes, if you claim the deduction without any verification.
  • What Should You Do? Request documentation. Explain that you cannot claim deductions without support. If the client refuses, consider declining the engagement.

On the Exam

Expect 3-4 questions on due diligence, typically:

  1. Scope Questions: "When must practitioners exercise due diligence?"
  2. Reliance Questions: "When can a practitioner rely on client-provided information?"
  3. Red Flag Questions: "Which situation requires further inquiry?"
  4. Consequences Questions: "What can result from a due diligence failure?"

The key is to remember: All IRS matters, reasonable care, can rely in good faith, but must inquire about red flags.

Test Your Knowledge

Under Circular 230, when must practitioners exercise due diligence?

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Test Your Knowledge

Can a practitioner rely on client-provided information?

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D
Test Your Knowledge

What should a practitioner do when client information appears incomplete?

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