Tax Planning Engagement Letter: What to Include (Template)

The plan went out in March. In June the client calls to ask why nobody changed the owner's payroll, why the retirement plan never got set up, and why the planning fee didn't cover the amended return. Nothing in the file says otherwise, because the firm never sent a tax planning engagement letter. It sent a return-prep letter and a meeting invite. A planning engagement fails the same way a compensation number does: a finished page reads the same whether the scope was agreed or not. The only way to check is to look at what was signed before the work started.

This guide covers what a planning letter needs to settle, a copy-ready template with bracketed fields, and the scope lines that keep a plan from turning into an open-ended service.

Why a planning engagement needs its own letter

A return-prep letter covers work on facts that already happened. The client hands over documents, the firm prepares the return, and the return is the deliverable. Planning doesn't work like that, and the differences are exactly what a letter has to pin down.

The deliverable is a recommendation, not a filing. The client is going to act on it: change a salary, fund a retirement plan, move money. Part of what it rests on is assumption, since next year's income is an estimate and the plan is only as current as the data behind it. And the value is harder to see. A client who pays for a return gets a return. A client who pays for a plan gets a document that says "do these four things," and six months later may not remember which four.

If planning lives inside the prep letter as one vague line ("tax planning as requested"), every one of those differences becomes an argument later. A separate letter, or a separate section with its own scope, deliverable and fee, closes them before the work starts. If you're building planning into a year-round service, the calendar side is covered in proactive tax planning for firms.

The eight sections of a tax planning engagement letter

Each section settles one question the client or the Reviewer would otherwise ask after delivery.

The deliverable section points to the report itself. What that report should contain, from baseline to sign-off, is its own article: what a tax plan deliverable should contain.

Tax planning engagement letter template (copy-ready)

Copy the paragraphs below into your firm's letter template and fill the bracketed fields. Keep the numbering; it matches the table above. Have your firm's counsel review the final wording before the first client signs it.

[FIRM LETTERHEAD]

[DATE]

[CLIENT NAME]

[CLIENT ADDRESS]

Re: Tax planning engagement for tax year [YEAR]

Dear [CLIENT NAME]:

This letter sets out the terms of the tax planning engagement between [FIRM NAME] ("we") and [CLIENT NAME] ("you").

1. Parties, entities and period. This engagement covers you, [SPOUSE NAME, IF ANY], and the following entities: [ENTITY NAME AND TYPE, e.g. S corporation]. It covers planning for tax year [YEAR]. It doesn't cover any other person or entity unless we add them in writing.

2. Scope of planning. We will analyze the following decisions: [LIST, e.g. owner salary and distributions; retirement plan options; accountable plan reimbursements; estimated tax payments; state considerations]. We'll base the analysis on your [PRIOR YEAR] return and the information you provide under section 4.

3. Deliverable. We will deliver one written planning report by [DATE OR "within [NUMBER] business days after we receive the items in section 4"]. The report will contain a baseline, the scenarios we compared, our recommendation, the assumptions behind it, the sources for each figure, and the name of the professional who reviewed and signed it. We will meet with you once, for up to [NUMBER] minutes, to walk through the report.

4. Your responsibilities. You agree to provide [LIST, e.g. the prior-year return, year-to-date payroll and books, retirement plan documents, the completed planning questionnaire] by [DATE]. You're responsible for the accuracy and completeness of that information. If your income, ownership, entity structure or state of residence changes after you send it, you'll tell us in writing, and we may need to update the report under section 6.

5. Use and disclosure of return information. [FIRM COUNSEL TO CONFIRM: whether IRC §7216 requires a separate written consent before return information is used or disclosed under this section.] Before we use or disclose your tax return information for any purpose other than preparing your return, including sharing it with [ADVISOR NAME OR "your financial advisor"], we'll ask you to sign any separate written consent the law requires. We won't share it until that consent is signed.

6. Fee basis. Our fee for this engagement is [FIXED FEE PER PLAN / TIERED PACKAGE: NAME / VALUE-BASED FEE AS DESCRIBED IN ATTACHMENT A], billed [TIMING]. The fee covers the scope in section 2 and the deliverable in section 3. If you ask us to add a decision, entity or scenario, or if the information in section 4 changes after we start, we'll confirm the change and any added fee in writing before we do the work.

7. Out of scope. Unless we add them in a separate letter or a written amendment, this engagement doesn't include: preparing or amending any tax return; implementing the recommendations (for example, changing payroll, adopting a retirement plan or setting up a reimbursement plan); responding to IRS or state notices; representation before any taxing authority; legal advice; investment advice; or updating the report after delivery.

8. Review, sign-off and limitations. [REVIEWER NAME, CREDENTIAL] will review and sign the planning report. You may rely only on the recommendations in the signed report, not on draft figures, emails or conversations. The report reflects the law and your information as of the date it's signed. Tax law changes, and we aren't responsible for updating the report for later changes unless you engage us to. Any tax savings shown are estimates based on the stated assumptions; actual results may differ.

Term and records. This engagement ends when we deliver the report and hold the meeting in section 3, or when either of us ends it in writing. Our workpapers belong to [FIRM NAME] and are kept under our records policy.

If these terms match your understanding, please sign below and return a copy.

[FIRM NAME]

By: [PARTNER NAME, TITLE] Date: [DATE]

Accepted: [CLIENT NAME] Date: [DATE]

In scope and out of scope, side by side

The out-of-scope list is the part clients read last and remember first. Put it in a table in the engagement kickoff email too.

If a client wants implementation, that's a second engagement with its own letter, fee and deliverable. Pricing both is covered in how to price tax planning services.

Who signs off, and on what

Two signatures matter, and they're different. The client signs the letter, which agrees the scope. The firm's Reviewer signs the report, which is the only thing the client may rely on. Section 8 of the template ties those together: no signed report, no reliance.

That's why the report needs a workpaper behind it. Each figure in the plan should trace to a source document or a stated assumption, and the Reviewer should be able to see both before signing. The owner's salary is the usual weak spot. If the plan includes a salary scenario for an S-corp owner, the letter's section 4 can list the reasonable compensation support as a client-provided or firm-prepared item, and the plan points to it. That support is what a Reasonable Compensation Study produces: every figure traced to its source, and a Reviewer's sign-off on the file. How salary, retirement and estimated tax fit together in the report itself is laid out in the S-corp tax planning memo.

When a financial advisor is part of the picture, the letter should say who receives the report and in what form. The advisor-to-firm side of that is in the financial advisor and CPA tax planning handoff.

Where planning letters break down

Many disputes over a planning engagement don't come from a bad recommendation. They come from a letter that didn't say enough.

• "Planning as requested." No named decisions means every new question is in scope.
• No data deadline. The plan gets built on last year's numbers because this year's never arrived.
• No reliance clause. The client acts on a figure from a call, not the signed report.
• No change trigger. A new entity or a mid-year sale gets absorbed into the original fee.

The fix for each one is a sentence in the template above. Collecting the data on time is easier with a standard intake, like the tax planning questionnaire.

Conclusion

A tax planning engagement letter does one job: it makes the scope checkable later. Name the decisions, the deliverable, the client's duties, the fee basis, the exclusions and the signer, and the June phone call has an answer on paper.

TracePrep ships one workflow today, the Reasonable Compensation Study, with traceable evidence and Reviewer sign-off on workpapers your firm owns. A tax-planning workflow is in development.

Get started or see how a Study is built.

Not tax advice. This article and template explain general practice as of 2026-09-23. They aren't legal advice. Your firm's counsel and the professional standards that apply to your firm govern the final letter.

TracePrep is a software product from TracePrep Inc., not a CPA firm. This content is operator experience for educational purposes; it is not tax advice and has not been reviewed by a licensed CPA. Consult a qualified tax professional for guidance on your specific situation. Source citations in TracePrep workpapers support audit defense but do not guarantee IRS outcomes.