Guide · Onboarding
Bookkeeping engagement letter: what to include
A clear engagement letter prevents most of the arguments a bookkeeping firm has with clients: about scope, due dates, late documents and fees. This guide lists what to cover and why each part saves you time later. It is a checklist, not legal wording.
Why it saves time, not just risk
Most time lost with a client comes from things nobody agreed: work that crept outside the scope, documents that arrive late, or questions about what the fee covers. When those are written down at the start, a reminder can point back to something the client already signed.
What to include
The parties and the start date
Who the firm is, who the client is, which entities are covered and when the engagement starts.
The scope of work
Exactly what you will do: which accounts, how often you reconcile, which reports you send and when. Name what is not included, such as tax returns, payroll or catch-up work, unless you are doing it.
What the client must do
What the client sends and by when, how they send it, and that they are responsible for the accuracy of what they provide.
Due dates and late documents
Your monthly due date for documents, and what happens when they arrive late, for example that the work moves to your next open slot.
Fees and payment
The fee, what it covers, how and when you invoice, how the client pays, and what happens if a payment is late.
Scope changes
How extra work is quoted and approved, so new accounts or requests move the client to a different fee instead of being absorbed.
Access and data
How you get access to the client's software, that each person uses their own login, and how you handle and store client data.
Communication
How clients reach you and how quickly you reply.
Ending the engagement
How either side can end it, what notice is needed, and what you hand over at the end.
Keep it current
Use one template for every client.
Change the scope section, not the whole letter.
Update it when the work changes.
A new service or a new fee deserves an updated letter.
Review it once a year.
Check it still matches how you actually work.
Get it reviewed.
Have a lawyer, or your professional body's guidance, check your template.
Common mistakes
A vague scope.
"Monthly bookkeeping" means different things to you and the client.
No rule for late documents.
Without one, a late client delays everyone else.
Fees without a scope.
A fee that doesn't say what it covers is hard to raise.
Never updating it.
An old letter that doesn't match the work protects nobody.
Questions
Do I need a separate letter for each client?
Use one template and fill in the client-specific parts, such as the scope, the entities and the fee.
Should catch-up work be in the same letter?
It's clearer to quote catch-up or cleanup work as a separate project, with its own scope and fee.
Can I use a template from the internet?
A template is a starting point. Have yours reviewed so it fits your services and the rules where you work.
See how much time unclear scope and late documents cost your firm.
The free Snapshot takes about 3 minutes and works from your own answers.