Accounting Engagement Letter Template: What to Include

An accounting engagement letter formalizes the relationship between your firm and a client before any work begins. It defines the services you'll provide, the fees you'll charge, and the limits of your responsibility -- so there's no confusion when the invoice arrives or when something goes wrong.

Unlike a bookkeeping engagement letter (which covers recurring monthly work), an accounting engagement letter may cover tax preparation, compilation, review, advisory services, or a combination. The template below is designed for general accounting services and can be adapted to any service type.

Accounting Engagement Letter Template

[Firm Name]
Engagement Letter for Accounting Services

Date: [Date]
Client: [Client Name / Business Name]
Prepared by: [Your Name, CPA/EA, Title]

Dear [Client Name],

This letter confirms the terms of our engagement to provide accounting services for [Client Name / Business Name] for the [tax year / fiscal year / period beginning [date]].

1. Services

We will provide the following services:

[Select and customize the applicable services below]

Tax preparation:
-- Prepare federal and [state] income tax returns for [entity type] for the tax year ending [date]
-- Prepare quarterly estimated tax payment calculations
-- Respond to IRS and state tax notices related to returns we prepared

Compilation services:
-- Compile [monthly/quarterly/annual] financial statements from information you provide
-- Financial statements will not be audited or reviewed, and no assurance is expressed

Advisory services:
-- Provide tax planning recommendations based on information you provide
-- Advise on entity structure, retirement plan options, and tax-saving strategies
-- Advisory services are based on current tax law, which is subject to change

Services NOT included: [List excluded services -- e.g., "audit or review engagements, legal advice, investment advice, payroll processing, bookkeeping services"]. These may be provided under separate engagement letters.

2. Your Responsibilities

You are responsible for:

-- Providing complete and accurate information and documentation for all services
-- Submitting all requested documents by the deadlines we communicate
-- Reviewing and approving all tax returns before filing
-- Maintaining adequate records to support all transactions reported on tax returns
-- Notifying us of significant changes to your financial situation, business operations, or entity structure
-- Keeping copies of all tax returns and supporting documentation

We will rely on the information you provide without independent verification. If the information is incomplete or inaccurate, our work product may be affected.

3. Fees

[Select the appropriate fee structure]

Fixed fee: The fee for the services described above is [$X], payable [upon completion / 50% upfront and 50% upon completion / monthly].

Hourly: Fees are billed at the following rates: [Partner: $X/hr, Manager: $X/hr, Staff: $X/hr]. We will provide an estimate before beginning work and notify you if the estimate will be exceeded.

-- Invoices are due within [30] days
-- Past-due balances accrue interest at [1.5%] per month
-- Out-of-scope work requires written approval and is billed at our standard hourly rates
-- We reserve the right to stop work if invoices remain unpaid beyond [60] days

4. Term and Termination

This engagement covers [specific period or tax year]. Either party may terminate with [30] days written notice. Upon termination, all fees for work completed to date are immediately due. Client records will be returned within [15] business days of final payment.

5. Limitations of Liability

Our services do not include procedures to detect fraud or errors. While we may identify issues during our work, we are not responsible for detecting all misstatements or irregularities.

We are not responsible for penalties, interest, or additional tax resulting from incorrect or incomplete information you provide, or from your failure to follow our recommendations.

[Firm Name]'s total liability under this engagement is limited to the fees paid for the services giving rise to the claim.

6. Confidentiality and Data Security

We will keep your information confidential under professional standards and applicable law. We will not share your information with third parties without your written consent, except as required by law, regulation, or professional standards (including peer review).

We use encrypted file transfer, secure cloud storage, and access controls to protect your data. [Optional: specify platforms used.]

7. Dispute Resolution

Any disputes arising from this engagement shall first be submitted to mediation. If mediation is unsuccessful, disputes shall be resolved by [binding arbitration / litigation in [jurisdiction]].

8. Acceptance

Please sign below to confirm your agreement to these terms. This letter supersedes any prior agreements related to these services.

_____________________________       _____________________________
[Client Name]                                [Your Name, CPA/EA]
Date: _________________                Date: _________________

How This Differs from Other Engagement Letters

Accounting firms use different engagement letters for different services:

• Accounting engagement letter (this template): Covers tax preparation, compilation, and advisory services. Flexible scope, typically annual or project-based.
• Bookkeeping engagement letter: Covers recurring monthly services -- transaction recording, reconciliation, financial reporting. Ongoing term with monthly billing.
• Audit engagement letter: Covers formal audit or review engagements with specific professional standards (GAAS, SSARS). Includes opinion language and management representation requirements.

Use the right letter for the right engagement. An audit engagement letter for a tax preparation client creates confusion -- the requirements and language don't match.

When to Use a New Engagement Letter

• New client: Always -- before any work begins
• Annual renewal: Issue a new letter each tax year, even for returning clients, to confirm scope and fees
• Scope change: If the client adds services (e.g., adds tax planning to a preparation-only engagement), issue an amended or supplemental letter
• Fee increase: A new letter documents the updated fee and the client's agreement to it
• Entity change: If the client restructures (e.g., sole prop to S-Corp), the new entity needs its own engagement letter

After the Letter Is Signed

The engagement letter is the starting point. Once signed:

1. Send the document request. For tax clients, send the tax document checklist immediately. For compilation clients, request access to the accounting software and prior-period financial statements.
2. Set up the client in your practice management system. Create the engagement, assign staff, and set deadlines.
3. Confirm the timeline. Share the document submission deadline and who the client should contact with questions.

For a complete onboarding workflow, see our accounting client onboarding guide.

Frequently Asked Questions

Is an engagement letter required for accounting services?

Not legally required in most states, but strongly recommended by the AICPA and most state CPA societies. Some professional liability insurance policies require written engagement agreements as a condition of coverage. Beyond legal protection, the letter prevents scope creep and fee disputes.

What should I do if a client refuses to sign the engagement letter?

Don't start the work. An unsigned engagement letter means no documented agreement on scope, fees, or liability limits. If the client objects to specific terms, negotiate. If they refuse to sign any written agreement, consider whether the engagement is worth the risk.

Can I use one engagement letter for multiple services?

Yes -- that's what this template is designed for. List each service in the scope section with its deliverables and fees. The alternative is separate letters for each service, which adds administrative overhead. One comprehensive letter is simpler for the client and easier to manage.

How should I deliver the engagement letter to clients?

Email with an electronic signature option (DocuSign, Adobe Sign, or similar) is the standard. Some firms include the engagement letter as part of onboarding document collection -- the client signs it alongside other intake forms, such as an accounting client intake form, through a secure document collection portal. Avoid mailing paper copies -- they delay the process and get lost.

What's the difference between an engagement letter and a retainer agreement?

An engagement letter defines services and terms for a specific engagement (e.g., "2025 tax return preparation"). A retainer agreement secures ongoing access to your time -- the client pays a monthly fee for a set number of hours, regardless of specific deliverables. Tax and accounting firms typically use engagement letters. Law firms and consultants more commonly use retainer agreements.