A tax preparation engagement letter is the written contract between a preparer and a client that fixes the scope of work, the fee, the responsibilities on each side, and the terms for ending the relationship. A complete letter covers services included and excluded, client obligations, preparer duties under Circular 230, fees and a liability cap, Section 7216 consent and data security, termination and dispute resolution, valid signatures, and retention. Skip any of these and you leave a gap that surfaces the moment something goes wrong.
Scope of Services
The scope section is the letter’s core. Without a firm boundary, clients assume the preparer is handling work that was never agreed to.
Name each return and schedule for the specific tax year. For an individual, that means Form 1040 and the applicable schedules, such as Schedule A for itemized deductions or Schedule B for interest and dividend income.1Internal Revenue Service. About Schedule B (Form 1040), Interest and Ordinary Dividends For a business, identify the entity type and its return: Form 1120 for a C corporation, Form 1120-S for an S corporation, or Form 1065 for a partnership.2Internal Revenue Service. Entities 4 – Filing Requirements for Partnerships and Corporations Self-employed clients need Schedule C for business income and expenses and Schedule SE for self-employment tax called out explicitly.3Internal Revenue Service. Schedule C and Schedule SE
List every state and local return the engagement includes. For clients with multi-state activity, require them to disclose all states where they earned income, owned property, or had employees, so filing obligations can be evaluated.
International forms deserve their own line. A missing Form 8938 starts at a $10,000 penalty, and a missing Form 5471 carries the same $10,000 initial penalty, with both climbing to $50,000 in continuation penalties if IRS notices are ignored.4Internal Revenue Service. International Information Reporting Penalties Neither side should be guessing whether these are in scope.
Estimated Payments and Extensions
State whether the preparer will calculate estimated tax payments for the following year using Form 1040-ES vouchers. Clients often assume this is automatic; if it isn’t, say so. Do the same for Form 4868 extensions: specify whether preparing one is part of the base fee or billed separately.
Services Not Included
Exclusions matter as much as inclusions. The most common one is audit representation. If the IRS or a state agency examines the return, responding is a separate engagement with its own fee. State clearly that the preparer is not performing an audit, review, or compilation of financial statements, not preparing financial projections, and not offering legal or investment advice. These exclusions block later claims that the preparer should have caught something outside tax return preparation.
Client Responsibilities
The client is responsible for the accuracy and completeness of the information they provide. Say this plainly in the letter. The client knows their income, deductions, and financial activity; the preparer builds the return on those facts.
List the documents the client must deliver: W-2s, 1099s, K-1s, records supporting claimed deductions, and anything else relevant to the return. Set a firm cutoff date. Without one, preparers get shoeboxes of receipts on April 10. If documents arrive after the deadline, the letter should say the preparer may need to file an extension and that any resulting delays fall on the client.
Require the client to review the draft return before filing. Signing Form 8879 authorizes electronic filing, and the signature carries a declaration under penalties of perjury that the return is “true, correct, and complete” to the best of the client’s knowledge.5Internal Revenue Service. IRS Form 8879 – e-file Signature Authorization The engagement letter should reinforce that reading the return before signing is the client’s job.
Preparer Obligations
Treasury Circular 230 requires practitioners to exercise due diligence in preparing returns, verifying representations made to the IRS, and communicating with clients about IRS matters.6eCFR. 31 CFR 10.22 – Diligence as to Accuracy Practically, that means asking follow-up questions when information looks incomplete or inconsistent with prior years. Noting this duty in the letter explains why the preparer may push for clarification.
Say that the preparer will apply current tax law to the facts the client provides and select appropriate forms, but will not independently verify or audit source documents. Detecting fraud is outside the scope of tax preparation and would require a separate forensic engagement.
Advising on Penalty Exposure
Circular 230 requires a practitioner to inform the client of any penalties reasonably likely to apply based on positions taken on the return, and to explain any opportunity to reduce that exposure through disclosure.7eCFR. 31 CFR 10.34 – Standards With Respect to Tax Returns and Documents, Affidavits and Other Papers The IRS imposes a 20% accuracy-related penalty on underpayments caused by positions lacking substantial authority.8Office of the Law Revision Counsel. 26 USC 6662 – Imposition of Accuracy-Related Penalty on Underpayments A taxpayer can reduce that exposure by adequately disclosing the position on Form 8275, as long as the position has at least a reasonable basis.9Internal Revenue Service. Instructions for Form 8275
State this in the letter: if the preparer identifies a position that might not hold up under scrutiny, the preparer will discuss it with the client and recommend disclosure where appropriate. That commitment protects the client from surprises and protects the preparer from later claims of failure to communicate risk. Preparers themselves face IRC 6694 penalties for signing returns with unreasonable positions.10Office of the Law Revision Counsel. 26 USC 6694 – Understatement of Taxpayers Liability by Tax Return Preparer
Fees, Payment Terms, and Liability
State the fee structure: fixed fee, hourly rate, or a hybrid. If hourly, disclose the rate for each person who may work on the return. Specify when payment is due, what payment methods are accepted, and what happens on nonpayment.
Circular 230 adds an important nuance. A preparer who is owed money generally must still return the client’s original records if the client needs them to meet federal tax obligations. The preparer may, however, withhold documents the firm created, including the completed return itself, until the client pays.11eCFR. 31 CFR 10.28 – Return of Clients Records Address this in the letter so the client understands both the preparer’s leverage and its limits. Form 8879 authorization, for instance, is firm-created and can be withheld pending payment.
Assign responsibility for IRS interest and late-filing or late-payment penalties to the client. Failure-to-file and failure-to-pay penalties under IRC 6651 belong to the taxpayer regardless of who prepared the return.12Office of the Law Revision Counsel. 26 USC 6651 – Failure to File Tax Return or to Pay Tax
Limitation of Liability
Many engagement letters cap the preparer’s total financial liability at the amount of fees paid for the engagement. That is standard across the accounting profession. Enforceability depends on state law and the circumstances, but including a cap gives courts a starting point. Specify whether the cap applies per claim or in the aggregate, and whether it covers only direct damages or also consequential losses. A cap set unreasonably low relative to the work performed is more likely to be challenged successfully.
Section 7216 Consent and Data Security
Tax preparers work under strict rules on client information, and the engagement letter is where the required disclosures live.
Restrictions on Disclosure and Use
IRC Section 7216 makes it a criminal offense for a preparer to disclose or use tax return information for any purpose other than preparing the return, unless the client consents or an exception applies. The penalty is up to one year in prison and a $1,000 fine.13eCFR. 26 CFR 301.7216-1 – Penalty for Disclosure or Use of Tax Return Information IRC 6713 adds a civil penalty of $250 per unauthorized disclosure, capped at $10,000 per calendar year. If identity theft is involved, those amounts rise to $1,000 per violation and a $50,000 annual cap.14Office of the Law Revision Counsel. 26 USC 6713 – Disclosure or Use of Information by Preparers of Returns
If the firm plans to use tax return information for anything beyond preparing the return, such as marketing other services, include a consent form that follows Treasury Regulation ยง 301.7216-3. The same applies when data is shared with third-party service providers for processing, cloud storage, or document exchange. Name each third party or category, and confirm they are contractually bound to protect the data.
Written Information Security Plan
The FTC Safeguards Rule, which applies to tax preparation firms, requires a written program with a designated security lead, a written risk assessment, encryption of customer data, multi-factor authentication, staff training, and a written incident response plan.15Federal Trade Commission. FTC Safeguards Rule: What Your Business Needs to Know Reference the firm’s information security program in the letter and describe the protocols used for transmitting sensitive documents, such as encrypted client portals rather than unprotected email.
Attach or include a privacy notice explaining how the firm collects, stores, shares, and disposes of client information. The Gramm-Leach-Bliley Act requires financial institutions, including tax preparers, to provide this notice and to safeguard nonpublic personal information.16Federal Trade Commission. Gramm-Leach-Bliley Act
Dispute Resolution and Termination
Specify how disputes will be handled. Many firms prefer mediation or binding arbitration to litigation because it is faster and less expensive. If arbitration is required, name the governing rules and the location of proceedings.
A termination clause should let either party end the engagement under defined circumstances. Common grounds for preparer termination include the client’s failure to provide necessary information, nonpayment, or discovery that the client has misrepresented material facts. The client should also have the right to terminate at any time, paying fees earned through the termination date. Say what happens to the client’s documents when the engagement ends, consistent with the Circular 230 duty to return client records on request.11eCFR. 31 CFR 10.28 – Return of Clients Records
Signing the Letter
Both the client and an authorized representative of the firm should sign before any substantive work begins. Starting preparation without a signed letter means working without the contractual protections the letter exists to provide.
Electronic signatures are valid under the Electronic Signatures in Global and National Commerce Act. To comply, the client must affirmatively consent to receiving records electronically, and the firm must disclose the client’s right to receive paper copies and to withdraw electronic consent.17Office of the Law Revision Counsel. 15 USC 7001 – General Rule of Validity The firm must also describe the hardware and software the client needs to access electronic records. Most e-signature platforms handle these disclosures, but verify that the platform’s workflow actually meets the requirements.
Retention and Annual Renewal
The IRS requires preparers to keep records related to tax return preparation, including due diligence documentation, for at least three years.18Internal Revenue Service. Due Diligence Requirements for Tax Preparers Consider a longer window. When a taxpayer omits more than 25% of gross income, the IRS has six years to assess additional tax.19Office of the Law Revision Counsel. 26 USC 6501 – Limitations on Assessment and Collection Many firms keep signed engagement letters for seven years for that reason. Firm policy should specify both the retention period and the secure storage method.
For recurring clients, write a new letter each year rather than rolling the old one over. Fees change, the client’s situation changes, and new forms or states may enter the picture. A fresh signature confirms both sides have reviewed the current terms. If truly nothing has changed, a short renewal notice referencing the prior year’s terms can work, but any change in scope or fees calls for a new letter.