An engagement letter is the single most important document in your client relationship. It defines what you’ll do, what you won’t do, what it costs, and what happens if things go wrong. Without one, you’re exposed to scope creep, billing disputes, and professional liability — all of which are entirely preventable.
This guide includes ready-to-use engagement letter templates for the most common accounting services, plus a breakdown of what to include, what to avoid, and how to get them signed faster.
Why Every Engagement Needs a Letter
Skipping the engagement letter is the most common mistake accounting firms make — especially small firms onboarding new clients quickly. Here’s what’s at stake:
Scope creep protection. Without a written scope, clients assume everything is included. “I thought you were handling my GST” or “Can you just take a quick look at my business partner’s return?” These requests pile up, and without a letter, you have no basis to push back or charge extra.
Billing clarity. An engagement letter that specifies fees, payment terms, and what triggers additional charges eliminates the “I didn’t know it would cost that much” conversation. Your fee becomes an agreement, not a surprise.
Professional liability shield. If a client claims you should have caught something or provided advice outside your scope, the engagement letter is your first line of defense. Professional indemnity insurers expect you to have one — and claims without an engagement letter in place are significantly harder to defend.
Regulatory compliance. Many professional bodies (CPA Australia, AICPA, ICAEW, etc.) require or strongly recommend engagement letters for all client engagements. It’s not optional — it’s a professional standard.
What to Include in Every Engagement Letter
Regardless of the service type, every engagement letter should cover these elements:
1. Parties Involved
Full legal names of your firm and the client entity. If you’re engaging with a company, specify the company name and the authorized representative signing on its behalf.
2. Scope of Services
Be specific. Don’t write “accounting services” — write exactly what’s included:
- Monthly bookkeeping (categorization of up to 200 transactions/month)
- Quarterly BAS/GST preparation and lodgement
- Annual financial statements and tax return
Equally important: what’s NOT included. Explicitly state exclusions to prevent scope creep:
- “This engagement does not include payroll processing, tax planning, or advisory services”
- “Any work outside the scope described above will be quoted separately”
3. Fees and Payment Terms
State the fee structure clearly:
- Fixed fee: “$X per month” or “$X per year”
- Hourly: “$X per hour, billed monthly in arrears”
- Hybrid: “$X per month for standard services, additional work billed at $X per hour”
Include payment terms (e.g., “due within 14 days of invoice”), accepted payment methods, and what happens with late payments.
4. Client Responsibilities
Your work depends on the client providing information on time. Spell it out:
- Deadlines for providing source documents
- Accuracy of information provided
- Timely responses to queries
- Consequences of late or missing information (e.g., “Late provision of records may result in additional fees or missed filing deadlines”)
5. Term and Termination
How long does the engagement last? How can either party end it?
- “This engagement is ongoing and may be terminated by either party with 30 days written notice”
- “Upon termination, all outstanding fees become immediately due”
6. Confidentiality
A brief statement confirming you’ll handle client information confidentially and in accordance with relevant privacy laws.
7. Limitation of Liability
Consult your professional body’s guidelines here. A standard clause limits your liability to the fees paid under the engagement or a reasonable multiple. This is important — don’t skip it.
8. Signatures and Date
Both parties sign and date. Electronic signatures are legally valid in most jurisdictions and dramatically speed up the process — no printing, scanning, or posting required.
Engagement Letter Templates
Copy and customize these for your firm. Replace everything in [brackets] with your specific details.
Template 1: Monthly Bookkeeping Engagement
Engagement Letter — Bookkeeping Services
Date: [Date]
From: [Your Firm Name], [Address] To: [Client Name / Business Name], [Address]
Dear [Client Name],
Thank you for choosing [Your Firm Name] to provide bookkeeping services for [Client Business Name]. This letter confirms our understanding of the terms and objectives of our engagement.
Scope of Services
We will provide the following services on an ongoing monthly basis:
- Categorization and reconciliation of bank and credit card transactions (up to [X] transactions per month)
- Monthly bank reconciliation
- Accounts payable and accounts receivable management
- Monthly financial reports (profit & loss, balance sheet)
- [BAS/GST/Sales tax preparation and lodgement — if applicable]
Services Not Included
This engagement does not include payroll processing, tax return preparation, financial forecasting, advisory services, or audit/assurance work. These services can be provided under a separate engagement if required.
Fees
Our fee for the services described above is $[amount] per month, payable within [14] days of invoice. Invoices will be issued on the [1st] of each month.
If your transaction volume exceeds [X] transactions in any month, additional transactions will be billed at $[amount] per [50] transactions.
Your Responsibilities
To enable us to perform our services effectively, you agree to:
- Provide access to your accounting software ([QuickBooks Online / Xero / other]) within [7] days of signing this letter
- Ensure all bank feeds are connected and up to date
- Respond to queries within [5] business days
- Provide receipts and supporting documentation when requested
Late provision of records may result in delays to your financial reports and potential additional fees.
Term and Termination
This engagement is ongoing from [start date] and may be terminated by either party with [30] days written notice. Upon termination, all outstanding fees become immediately payable.
Confidentiality
We will treat all information provided by you as confidential, except where disclosure is required by law or professional obligations.
Limitation of Liability
Our liability under this engagement is limited to the total fees paid for the [12]-month period preceding any claim. We are not responsible for any loss arising from inaccurate or incomplete information provided by you.
Acceptance
Please sign below to confirm your acceptance of these terms. If you have any questions, please contact us before signing.
______________________________ ______________________________ [Your Name], [Your Firm Name] [Client Name], [Client Business Name]
Date: __________________ Date: __________________
Template 2: Annual Tax Return Engagement
Engagement Letter — Tax Return Preparation
Date: [Date]
Dear [Client Name],
This letter confirms our engagement to prepare your [individual / company / trust / partnership] income tax return for the financial year ending [date].
Scope of Services
We will prepare and lodge your income tax return based on information you provide. This includes:
- Preparation of your [individual / business] income tax return
- Calculation of tax payable or refundable
- Lodgement with [ATO / IRS / HMRC / relevant authority]
- Advice on payment due dates
Services Not Included
This engagement is limited to tax return preparation. It does not include:
- Tax planning or structuring advice
- Review of prior year returns (unless separately agreed)
- Representation in the event of an audit or review
- Bookkeeping, financial statements, or any other services
If you’d like to discuss additional services, we’re happy to provide a separate quote.
Fees
Our fee for preparing and lodging your tax return is $[amount]. [For more complex returns, our fee will be confirmed after reviewing your information, typically ranging from $X to $Y.]
Payment is due within [14] days of invoice.
Your Responsibilities
You are responsible for providing complete and accurate information for the preparation of your return. This includes:
- All income sources (employment, investment, rental, business)
- Deduction claims with supporting receipts or records
- Details of any significant transactions or changes during the year
- Prior year tax return and notice of assessment (if you are a new client)
Please provide all information by [date]. Late provision may delay your return and could result in late lodgement penalties, which are your responsibility.
Limitation of Liability
We will prepare your return based on the information you provide. We are not responsible for the accuracy or completeness of your source data. Our liability is limited to the fees paid for this engagement.
Term
This engagement covers the [year] financial year only. A new engagement letter will be issued for subsequent years.
Acceptance
Please sign and return this letter to confirm your agreement. You can sign electronically — we’ll send a signing request to your email.
______________________________ ______________________________ [Your Name], [Your Firm Name] [Client Name]
Template 3: Advisory / CFO Services Engagement
Engagement Letter — Advisory Services
Date: [Date]
Dear [Client Name],
We’re pleased to confirm our engagement to provide advisory services to [Client Business Name].
Scope of Services
We will provide the following advisory services:
- Monthly financial review meeting ([30/60] minutes)
- Cash flow forecasting and monitoring
- Budget preparation and variance analysis
- KPI tracking and reporting
- Ad-hoc financial guidance via email or phone (up to [X] hours per month)
Services Not Included
This engagement does not include bookkeeping, tax return preparation, audit services, or legal or investment advice. These can be arranged separately if needed.
Fees
Our advisory fee is $[amount] per month, billed on the [1st] of each month and payable within [14] days.
Additional hours beyond the included [X] hours will be billed at $[amount] per hour.
Your Responsibilities
For us to provide meaningful advice, you agree to:
- Maintain up-to-date bookkeeping records (or engage us separately for this)
- Attend scheduled monthly meetings or provide [48] hours notice of rescheduling
- Share relevant business developments, plans, or concerns in a timely manner
Confidentiality
All discussions and information shared during this engagement will be treated as strictly confidential.
Term and Termination
This engagement begins on [date] and continues month-to-month. Either party may terminate with [30] days written notice.
Acceptance
Please sign below or reply to this email confirming your acceptance.
______________________________ ______________________________ [Your Name], [Your Firm Name] [Client Name], [Client Business Name]
Template 4: Compilation / Financial Statements Engagement
Engagement Letter — Compilation of Financial Statements
Date: [Date]
Dear [Client Name],
This letter confirms our engagement to compile the financial statements of [Client Business Name] for the year ending [date].
Scope of Services
We will compile your financial statements based on information you provide. This includes:
- Balance sheet / statement of financial position
- Profit and loss statement / income statement
- Notes to the financial statements (as required)
A compilation involves presenting financial information in the form of financial statements without expressing an opinion or providing assurance on the accuracy of the information. We are not performing an audit or review.
Your Responsibilities
You are responsible for the accuracy and completeness of the underlying financial records. You are also responsible for all business and financial decisions, and for the preparation and fair presentation of the financial statements.
Fees
Our fee for the compilation is $[amount], payable within [14] days of invoice.
Limitation of Liability
Since this is a compilation engagement and not an audit or review, we do not express an opinion or provide any assurance on the financial statements. Our liability is limited to the fees paid for this engagement.
Acceptance
Please sign and return this letter to proceed.
______________________________ ______________________________ [Your Name], [Your Firm Name] [Client Name]
Common Engagement Letter Mistakes
Being too vague about scope. “We will provide accounting services” means different things to different people. Be specific about what’s included AND what’s excluded. The five minutes it takes to list exclusions will save you hours of scope creep conversations.
Forgetting to address late or missing information. If a client sends their records two months late, who bears the consequences? Your letter should state that late information may result in delayed service and additional fees.
Not updating the letter annually. Services change, fees change, regulations change. Send a fresh engagement letter at the start of each financial year or whenever the scope changes materially. Don’t rely on a letter signed three years ago.
Making it too long and legalistic. A 10-page letter full of legal jargon that no one reads is worse than a clear 2-page letter that both parties understand. Write for your client, not for a lawyer. Keep the language plain and direct.
Not getting it signed before starting work. This is the most common mistake. You start work while the letter is “being reviewed” and before you know it, six months of work has been done without a signed agreement. Make it a firm policy: no signed letter, no work starts. Use electronic signatures to remove friction — clients can sign from their phone in 30 seconds.
How to Get Engagement Letters Signed Faster
The number one reason engagement letters don’t get signed is friction. Every extra step — print, sign, scan, email — is an opportunity for the client to put it in the “later” pile.
Send for e-signature immediately. Don’t attach a PDF and ask the client to print and sign. Use electronic signature tools that let them sign with a tap. Most clients will sign within 24 hours if it’s easy.
Include it in your onboarding workflow. Make the engagement letter the first step in your client onboarding checklist. It should be sent automatically when a new client is added, and the onboarding shouldn’t proceed until it’s returned.
Set a reminder. If it’s not signed within 3 business days, send a follow-up. After 7 days, call. Don’t let it sit in limbo — an unsigned engagement letter is a ticking liability.
Keep it short. A 2-page letter gets signed faster than a 10-page letter. Include the essentials (scope, fees, responsibilities, termination, liability), skip the unnecessary legalese, and add a detailed terms & conditions document as an appendix if your professional body requires it.
When to Issue a New Engagement Letter
Don’t treat the engagement letter as a one-time document. Issue a new one when:
- A new financial year begins — Even if nothing changes, an annual re-signing confirms the relationship is active and the terms are current
- The scope changes — Adding payroll to a bookkeeping engagement? New letter (or a signed amendment)
- Fees increase — Pair your fee increase letter with an updated engagement letter reflecting the new rates
- The client entity changes — New business structure, ownership change, or new contact person? New letter
- You’re moving to fixed-fee pricing — If you’re transitioning from hourly to productized services, the engagement letter needs to reflect the new model
Frequently Asked Questions
Is an engagement letter legally binding?
Yes. An engagement letter is a contract between your firm and the client. Once both parties sign, it creates legally enforceable obligations on both sides. This is why it’s important to get the terms right and ensure both parties understand what they’re agreeing to.
Do I need a separate engagement letter for each service?
Not necessarily. You can cover multiple services in a single letter — just make sure each service has its own scope description and fee. Some firms prefer separate letters for clarity, especially when services are added at different times.
What if a client refuses to sign?
This is a red flag. A client who won’t commit to a written agreement is more likely to dispute fees, expand scope without paying, or create professional liability issues. Consider whether you want to take on a client who won’t agree to basic terms. In most cases, the answer should be no.
Can I use the same template for every client?
Use the same structure, but customize the scope and fees for each client. The templates above are starting points — adjust them to match each client’s specific situation. A bookkeeping client with 50 transactions/month needs different terms than one with 500.
How should I store signed engagement letters?
Store them digitally, linked to the client record in your practice management software. You should be able to find any client’s current engagement letter in under 30 seconds. If you can’t, your filing system needs work.