Engagement Letters: Scope, Fees and Responsibilities

An engagement letter is the written agreement between a professional firm and its client for a specific piece of work. It must say what is included and what is not, what the fees are and how they are billed, what the client has to provide, who owns the output, how long the engagement runs and how either side can end it. It is short by tradition and binding in fact.

Why the short document matters

Professional engagements go wrong in a predictable way: the work grows, the fee does not, and each side remembers a different conversation about what was included. The engagement letter exists to make that conversation retrievable. It also protects the client — a firm that will not put its scope and fees in writing is telling you something.

What an engagement letter must include

• The parties, and which entity in a group is actually the client.
• The scope — the specific work, described so both sides could agree when it is complete.
• Exclusions — what is expressly not included. The most useful paragraph in the letter.
• Fees: fixed, hourly with an estimate, retainer, or contingent, and what expenses are charged.
• Billing rhythm, payment window, and what happens if an invoice goes unpaid.
• Client responsibilities: information, access, approvals, and timeliness.
• Who does the work, and whether any of it may be subcontracted.
• Confidentiality, conflicts, and how records are kept and returned.
• Ownership of and licence to use the deliverables.
• Limitation of liability, and any professional insurance the firm carries.
• Term and termination on both sides, including what is owed for work in progress.
• How disputes are handled, and under whose law.

What to look for

• Does the scope describe an outcome, or an open-ended relationship?
• Are exclusions written down, or only implied by what the scope does not mention?
• For hourly work: is there an estimate, and a duty to warn before exceeding it?
• Are expenses and third-party costs marked up, and is the markup disclosed?
• Does a retainer get applied to fees or held to the end?
• Is there an annual rate increase, and does it need your agreement?
• Does the letter incorporate a proposal, standard terms, or a schedule you have not read? Ask for them.
• Is termination mutual, with reasonable notice, and are files returned promptly on exit?
• Is there a liability cap, and is it a number you can live with given the value of the work?

The clauses that cause disputes

Scope drift

The classic pattern is a letter written for one defined task that gradually covers a much larger relationship, without anyone re-papering it. Both sides lose: the firm works unpaid hours, the client receives an unexpected invoice. The fix is a habit rather than a clause — when the work materially changes, send a short update to the letter. A two-paragraph amendment prevents an argument that costs both sides more than the work.

Fee estimates presented as fees

An estimate is not a cap unless the letter says so. If the client heard a number and the firm meant a guide, an unhappy conversation is scheduled. Say which it is: a fixed fee, a not-to-exceed figure, or an estimate with an obligation to flag before passing it. Ambiguity here damages the relationship far more than the money involved.

Incorporated terms nobody read

Many engagement letters attach standard terms carrying the substantive risk allocation — the liability cap, the indemnity, the dispute clause. They are part of what you sign. Ask for them before signing, and read them once; they usually change little from engagement to engagement, so the reading is a one-off cost.

Termination and the file

Endings need to be workable. Check the notice period, what is payable for work in progress, and — often the real issue — how quickly the client gets their records, data and work product back, and in what format. A letter that is silent on the return of the file turns a routine change of adviser into a standoff.

An engagement letter is worth doing well precisely because it is short: an hour spent on scope and exclusions removes most of the friction that arrives later. Keep the signed version somewhere you can find it, and update it when the work changes. This guide is general information rather than legal advice; professional obligations and permitted fee arrangements vary by profession and by state.