Engagement letter: the document that decides who was right later

An engagement letter is the written agreement between a professional firm and a client setting out what work will be done, what will not, who does what, how fees are calculated and how the relationship ends. Accountants, auditors, lawyers, consultants and agencies all issue one, and in several professions issuing one is a requirement of the regulator rather than a matter of preference.

Its practical function is narrower than it looks. It is not there to be read while the work goes well. It exists for the day the client says the firm was supposed to do something the firm believed was outside the engagement — and on that day, the only thing that decides the argument is what the letter says about scope.

What an engagement letter must settle

• The parties, precisely: which legal entity is engaged and which entity is the client. Groups of companies produce most of the confusion here.
• Scope of services, in specifics — and an explicit list of what is excluded. The exclusions do more work than the inclusions.
• The period covered, and whether the engagement is recurring or one-off.
• Fees: the basis, the rates, what triggers extra charges, expenses, and when invoices are issued and due.
• Client responsibilities: what information is provided, in what form and by when. Late client input is the most common cause of a missed deadline and the least often documented.
• Limitations: what the firm is not opining on, reliance by third parties, and any cap on liability where the profession and jurisdiction allow one.
• Confidentiality, data protection and who may see the work.
• Conflicts of interest and how they will be handled if one arises.
• Termination: notice on either side, and what happens to fees and work in progress.
• Complaints procedure and governing law.

Exclusions are the valuable half

A scope written only as what the firm will do invites the client to assume everything adjacent is included. The letter that prevents disputes says plainly what is not covered: we are preparing the accounts, we are not auditing them; we are advising on the contract, we are not advising on the tax treatment; we will file the return, we will not check the underlying records. Naming the obvious exclusion feels awkward when the relationship is new, and it is exactly the sentence that settles the argument two years later.

Send the letter before the work starts, not after. A letter signed at the point the invoice is questioned is worth very little, and in regulated professions starting work without one can be a finding in itself.

The audit engagement letter is a stricter case

An audit engagement letter is governed by auditing standards rather than by preference, and it has required content: the objective and scope of the audit, the auditor’s and management’s respective responsibilities, the inherent limitations of an audit, the form of the report expected, and management’s obligation to provide access and a written representation letter. It also does something the general version does not — it manages the expectation gap, by stating that an audit is not designed to detect every fraud. Firms reissue it when the engagement changes or when a recurring client’s circumstances shift, and many reissue annually as a matter of routine.

Keeping the version that was signed

Firms rarely lose engagement letters. They lose track of which version applies — the letter was updated for a new service, the scope changed in an email nobody filed, and two documents now describe the relationship. Ettex Docs holds the letters with version history so what was in force on a date is recoverable, Ettex Signature collects the client signature without a printing round, and Ettex Records keeps one file per client with the letter, the variations and the client due diligence file attached.

Being direct: this is not legal advice and not a template library. What your engagement letter must contain is set by your professional body, your regulator and your jurisdiction, and the liability provisions in particular are worth having drafted properly once rather than copied.