How IRS Circular 230 due diligence rules shape bookkeeping firm work

What to take away

What Circular 230 actually covers for a bookkeeping firm

Circular 230 is the Treasury Department's rulebook for practice before the IRS. It applies to attorneys, CPAs, enrolled agents, enrolled retirement plan agents, enrolled actuaries and other practitioners who represent clients or prepare and file returns.

A bookkeeping firm enters this world when it prepares or transmits federal returns, signs as a preparer, or gives written tax advice the client relies on. The rules do not cover every bookkeeping task, but they cover the tax work that grows out of the books.

OPR administers the rules and handles discipline, as the Office of Professional Responsibility and Circular 230 | Internal Revenue Service page explains. OPR can caution, suspend or disbar a practitioner, and it can also impose monetary penalties in some cases.

For a firm, the practical effect is that tax preparation work is not just a service line. It is regulated conduct. The firm needs to know who in the office is a practitioner and what each person is allowed to do.

Circular 230 also sets duties around competence (§10.35), diligence as to accuracy (§10.22), confidentiality, conflicts of interest (§10.29) and written advice (§10.37). A firm that prepares returns should map those duties to its actual workflow, not to a general policy binder. See the compliance checklist for new owners for a starting structure.

The Circular 230 sections that carry the due diligence duties

Circular 230's due diligence and related practice rules are found in specific sections. §10.22 requires diligence as to accuracy. §10.34 sets standards for tax returns, documents, affidavits and other papers. §10.35 requires competence. §10.36 requires procedures to ensure compliance. §10.37 sets requirements for written advice. §10.21 addresses knowledge of a client's omission. §10.29 governs conflicts of interest. §10.51 defines incompetence and disreputable conduct, and §10.52 lists violations subject to sanction.

For a bookkeeping firm, these sections map to review, documentation, competence, conflict checks and written advice controls. Form 8867 due diligence is a separate Internal Revenue Code preparer requirement under IRC §6695(g); it sits alongside Circular 230 and is not the same as §10.22 diligence.

Who counts as a practitioner under OPR oversight

A practitioner is a person who is eligible to practice before the IRS and who files a declaration of representative. CPAs, attorneys and enrolled agents are the common categories. Enrolled actuaries and enrolled retirement plan agents have narrower scopes.

An unenrolled bookkeeper who prepares a return is not automatically a practitioner under Circular 230. But the firm may still be subject to preparer rules in the Internal Revenue Code, and the signing preparer takes on specific duties.

This split matters for staffing. If a firm owner is a CPA or enrolled agent, the owner is a practitioner. If an employee prepares returns under review, the firm should know whether that employee signs, transmits, or only assembles workpapers.

The Tax professionals | Internal Revenue Service hub covers Circular 230, due diligence and e-file duties in one place, which helps a firm sort roles. The link between role and rule is the first thing OPR or an examiner will test.

Firm owners should also check state licensing. State boards of accountancy and state CPA licensing requirements can add rules on top of Circular 230. A firm operating in California, Texas or Florida may face different state-level duties than one in Illinois or Colorado. The licences, filings and checks guide covers that overlap.

Due diligence duties that reach bookkeeping engagements

Circular 230 §10.22 requires diligence as to accuracy in preparing or assisting with tax returns and other documents. That is broader than the credit-specific due diligence rules under the Internal Revenue Code, which are enforced through Form 8867. A bookkeeping firm can face both layers when it prepares a return.

The Internal Revenue Code adds a separate preparer due diligence penalty for the earned income tax credit, the child tax credit, the additional child tax credit, the American opportunity tax credit and the credit for other dependents. These are the credits tied to Form 8867, and the penalty is separate from Circular 230 discipline.

A bookkeeping firm often holds the source records for those claims. Payroll records, invoices, bank statements and client questionnaires feed the return. If the firm prepares the return, the due diligence duty attaches to the preparer, not to the client.

That means the firm should collect and review records that support income, expenses, dependency and credit eligibility. A client statement alone may not be enough. The firm should document what it asked for and what it received.

A practical test is whether a reviewer could reconstruct the basis for each position from the file. If the answer is no, the file is weak. For day-to-day habits, see SOPs: the daily checklist.

Documenting client records and Form 1099/W-2 filings

Documentation of client records is the backbone of Circular 230 compliance. The firm should keep engagement letters, client-provided records, questions asked, answers received, and the final return or information return.

For information returns, the firm must handle Form 1099 and W-2 filing requirements. Form 1099-NEC reports nonemployee compensation. Form 1099-MISC covers rents, royalties and other payments. Form W-2 reports wages for employees.

The deadlines depend on the form and the filing method. Form W-2 is due to employees by January 31. The SSA copy of Form W-2 is due by January 31 if filed on paper, but electronically filed W-2s are due to the SSA by March 31. Form 1099-NEC is due to recipients and to the IRS by January 31. Other 1099 series forms, such as Form 1099-MISC, are due to recipients by January 31 and to the IRS by February 28 if filed on paper or March 31 if filed electronically. Electronic filing is required above certain thresholds, and paper filing has lower thresholds.

The Forms & instructions | Internal Revenue Service page is the place to confirm the current version of each form and its instructions. A firm should build a calendar around those dates, not around client reminders.

A bookkeeping firm that files these forms for clients should also collect W-9s and verify taxpayer identification numbers. Missing or wrong numbers create backup withholding problems and amended filings.

Here is a checklist a firm can use for each client with information return work:

Penalty exposure under Form 8867 and preparer rules

The Form 8867 due diligence checklist is required for the credits listed earlier. The preparer must complete it, keep it, and ask the client the questions it contains. The form is not filed with the return in most cases, but it must be available if the IRS asks. Form 8867 turns the duty into five required actions: complete the form, ask the taxpayer the questions it contains, document the taxpayer's answers, keep records that support the answers, and retain the completed Form 8867. The questions cover the facts that determine eligibility for the credit claimed, including income, relationship, age, residency and dependency. If the client's answers or documents do not support the credit, the preparer should not claim it.

The Instructions for Form 8867 (11/2025) | Internal Revenue Service set out the penalty rules. A preparer who fails to meet due diligence requirements can face a penalty for each failure, and the penalty can apply to each credit claim. The amount is adjusted for inflation, so firms should check the current instructions.

Penalties can also apply for other conduct: signing a return the preparer did not prepare, failing to sign, or failing to provide a copy to the client. These are separate from the credit due diligence penalty.

A firm should treat the checklist as a control, not a formality. If the preparer cannot answer a question from the file, the return should not be filed until the gap is closed.

A worked example helps. Suppose a client claims the earned income tax credit. The firm has payroll records showing low wages and a client statement about a child. The preparer completes Form 8867, asks the required questions, and keeps the answers.

If the client cannot show the child lived with them, the firm documents the inquiry and does not claim the credit. That record is the defense if the IRS later asks.

E-file duties and IRS tax professional obligations

IRS e-file for tax professionals is the standard channel for transmitting federal returns. An Electronic Return Originator (ERO) must be authorized, and the firm must follow the rules in Publication 3112 and the e-file provider agreement.

An ERO must verify the taxpayer's identity, obtain a signed Form 8879 or equivalent, and retain records. The firm must also monitor acknowledgments and correct rejected returns within the allowed window.

E-file duties interact with Circular 230. A practitioner who transmits a return is practicing before the IRS. Poor e-file hygiene, such as filing without a signed authorization, can lead to sanctions.

E-file for tax professionals | Internal Revenue Service collects e-file and due diligence resources in one place. Firms should assign an e-file administrator and a backup, so deadlines do not depend on one person.

E-file also creates a data trail. The firm should keep transmission reports, acknowledgments and client authorizations with the return file. That trail supports both the e-file rules and the Circular 230 duty to keep records. For how to set service expectations around these steps, see how to document bookkeeping firm service standards.

Building a Circular 230 compliance file for each client

A per-client compliance file is the simplest way to show the firm met its duties. The file should live with the engagement, whether digital or paper, and should be reviewed before filing.

Start with the engagement letter and the client's identity information. Add the source records used for the books and the return. Then add the forms, checklists and authorizations.

Numbered steps for building the file:

The file should also record any advice the firm gave in writing. Circular 230 §10.37 sets the requirements for written tax advice: the advice must be based on reasonable factual and legal assumptions, use reasonable efforts to identify and ascertain the relevant facts, and not rely on unreasonable assumptions. A copy in the file shows what was said and what facts supported it.

A firm with several preparers should use a common index so any reviewer can find the same items. That is also how the firm prepares for OPR inquiries or IRS examinations. For a review framework, see service quality.

States with their own rules, such as California, Texas and New York, should have their extra items added to the same file. State boards of accountancy, the AICPA and NASBA publish standards that may apply. FinCEN beneficial ownership information reporting and the FTC Safeguards Rule can also affect client records held by the firm.

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