Client asks for bank reconciliation services. You agree. Two months later, they’re demanding full financial reporting and questioning why you’re charging extra. Sound familiar?
This scenario happens because bookkeepers skip the most basic protection tool available to them: a properly drafted engagement letter. The document defines your services, protects your fees, and prevents scope creep before it starts.
This guide shows you exactly what belongs in a bookkeeping engagement letter, why you need one for every client relationship, and how FigsFlow generates professional, legally sound letters in under 30 seconds. You’ll also find templates, real case studies, and practical steps to implement today.
Key Takeaways for Busy Bookkeepers
- Engagement letters are legal contracts that define services, fees, and responsibilities between bookkeeper and client
- Every client needs a signed letter before you begin work to protect both parties from disputes
- Letters must include 10 core elements covering scope, limitations, fees, data protection, and termination terms
- Digital signatures are legally binding in the UK, making electronic letters as valid as paper versions
- FigsFlow generates compliant letters in 3 steps taking approximately 30 seconds from start to send
What is a Bookkeeping Engagement Letter?
A bookkeeping engagement letter is a formal written agreement establishing the professional relationship between you and your client. It functions as a binding contract outlining exactly what bookkeeping services you will deliver.
The letter specifies deliverables such as transaction categorisation, bank reconciliation, VAT return preparation, or payroll processing. More importantly, it states what you will not provide, preventing clients from assuming services you never agreed to perform.
Think of it as your professional boundary document. Without these boundaries documented in writing, clients inevitably expect more than you intended to deliver. The engagement letter creates mutual understanding before money changes hands or work begins.
Unlike informal proposals or quotes, engagement letters carry legal weight. Courts recognise them as enforceable contracts when fee disputes or service disagreements arise. This protection works both ways, safeguarding you from unreasonable client demands and protecting clients from unclear service terms.
❓ Confused About Engagement Letters vs Letters of Intent?
You’re not alone. Many bookkeepers mistakenly use these terms interchangeably. An engagement letter (LOE) is legally binding and defines your service relationship. A letter of intent (LOI) simply expresses interest before negotiations begin. Understanding this difference protects your practice.
Why Bookkeepers Need an Engagement Letter
Clear documentation separates professional bookkeeping practices from amateur operations. An engagement letter establishes you as a serious professional who understands business relationships require formal agreements.
- Prevents Scope Creep Immediately – Defines exactly what services you provide and what falls outside your agreement
- Provides Legal Protection in Disputes – Serves as indisputable evidence when fee or service disagreements arise
- Ensures GDPR Compliance – Includes privacy notices explaining how you handle sensitive financial data
- Demonstrates Professional Competence – Signals you operate a legitimate practice with proper procedures
- Clarifies Payment Terms Upfront – Specifies fees, billing frequency, and payment deadlines to prevent disputes
Every successful bookkeeping relationship starts with mutual understanding. Engagement letters create this foundation by documenting expectations in clear, enforceable terms.
Real-Life Case Study: How an Engagement Letter Saved £12,000
Sarah, a Manchester-based bookkeeper, quoted £300 monthly for basic transaction categorisation. Three months in, her retail client began requesting cash flow forecasts, inventory reconciliations, and consolidated reports.
Sarah hesitated to bill for the extra work, worried about damaging the relationship. By month six, she'd provided £12,000 worth of unbilled services. When she raised the issue, the client claimed these services were implied in the original agreement.
Without an engagement letter defining her exact deliverables, Sarah had no written proof. She wrote off the £12,000 to maintain the relationship.
A simple engagement letter stating "transaction categorisation and bank reconciliation only" would have given Sarah written proof when additional requests arose. She could have referenced it immediately, establishing that new services required separate agreements and additional fees.
Key Elements of a Bookkeeping Engagement Letter
Consider each component of your bookkeeping engagement letter as an integral part of your professional service offering.