A project letter does not govern a retainer relationship.
A tax return engagement has a natural endpoint. A bookkeeping engagement does not. That changes what the letter needs to cover.
The scope has to define what you deliver each month and what you do not. It needs to address what happens when the client is late delivering documents. It needs a termination clause that gives both parties a defined exit with adequate notice, not just “either party may terminate.”
Most engagement letter templates were written for project-based work. Applied to a monthly retainer, they leave the terms of the ongoing relationship undefined.
What a bookkeeping engagement letter should cover.
Scope of services
Specify what you deliver: transaction categorization, bank and credit card reconciliation, monthly financial statements. State what is not included: tax return preparation, payroll processing, accounts payable management, financial advisory services. If additional work falls outside this scope, define how it is billed.
Document delivery requirements
The client is responsible for providing bank statements, receipts, and supporting documentation by a defined cutoff each month. A missed cutoff delays your deliverables. The letter should say that explicitly and put the responsibility where it belongs.
Fee and billing terms
Monthly retainer amount, billing date, and what happens when payment lapses. Most practitioners pause services after 15 days past due. That threshold belongs in the letter.
Term and termination
This engagement continues month to month until either party gives written notice. Specify the notice period. State what work is owed through the termination date. An open-ended retainer with no defined exit is a liability for both parties.
Limitation of liability
You are categorizing and reconciling the information the client provides. You are not auditing it. The letter should state that your work relies on the accuracy of client-provided records and that errors in the underlying data are the client’s responsibility.
Generate the letter in minutes.
Enter the client name, entity type, monthly fee, and payment terms. Use the scope notes field for anything non-standard: additional services, specific exclusions, or unusual client circumstances. EngageDraft generates a letter that covers the sections above, designed around AICPA guidelines for bookkeeping engagements.
Review the output. Edit anything that needs adjusting. Send for e-signature. Your client signs from their device. The signed record is stored in your dashboard.