Bookkeeping firm due diligence

Once a bookkeeping firm purchase is under letter of intent, the diligence that matters most is not accounting-heavy in the way it would be for a manufacturer or a retailer — it is verifying that the client relationships, the documentation and the systems actually match what the seller has represented.

Verify engagement scope client by client

Where written engagement letters or scope agreements exist, read them directly rather than relying on the seller’s revenue summary, and where none exist, treat that gap as a real finding — revenue attached to an undocumented, informal engagement is much harder to defend if a client disputes billing after the sale. Cross-check billed fees against actual client activity for at least the most significant accounts before relying on the seller’s numbers.

Check for CRA remittance and filing problems tied to the business

A bookkeeping firm that processes payroll or files GST/HST on behalf of clients is itself a business with its own remittance and filing obligations, and outstanding CRA debts or unresolved filing issues can attach to the business you are buying, not just to the seller personally. Confirm the firm’s own filing and remittance status is current as part of diligence, using the appropriate search and confirmation channels rather than taking the seller’s word for it.

Confirm who actually controls the software and the data

Because client bookkeeping data lives inside cloud-accounting platforms tied to specific logins, confirm precisely which accounts are firm-controlled versus personally controlled by the seller, and confirm what happens to client data and access if that distinction is not as clean as represented. Client financial data is personal and business information subject to Canadian privacy law, and a firm without a clear, documented approach to who can access it is a real finding, not a minor administrative gap.

Test the work itself, not just the paperwork around it

Written engagement letters, a single software platform and clean CRA filings can all check out and the client books themselves can still be wrong. Pull a sample of active client files directly — files you choose, not ones the seller selects for you — and confirm reconciliations are current, that GST/HST filings tie out to what the books actually show, and that there is no backlog of uncorrected entries sitting in the accounts. A firm can look immaculate on documentation and still be quietly delivering inaccurate books to several clients, and that is a liability and reputation risk that transfers to you the moment those clients become yours, not something a documentation review alone will ever surface.

Check the firm’s history processing remittances on clients’ behalf, not just its own

The CRA-filing check most buyers already run covers the firm’s own business number and payroll account, but where the firm also files GST/HST returns or remits payroll deductions on behalf of clients, that is a second and distinct compliance history worth its own inquiry. Ask specifically whether the firm has ever made a remittance error on a client’s account, how it was caught, and how it was resolved — an error made processing a client’s own payroll exposes that client to CRA penalties and interest, and a client let down that way once is a retention risk regardless of what the engagement letter says.

Review how staff, not just the owner, are actually engaged

Where the firm employs bookkeepers beyond the owner, pull their employment or contractor agreements and confirm the classification is genuinely correct rather than a label of convenience — a bookkeeper treated as an independent contractor who functions, in practice, like an employee can leave the buyer holding a misclassification finding, with the back pay and remittance exposure that comes with it, well after closing. Confirm as well whether any staff member holds a personal, undocumented relationship with a major client that the purchase price is quietly counting on.

What a documentation gap actually tells you

Finding that client relationships, procedures or software access are undocumented is not automatically a reason to walk away, but it changes what you are actually buying — you are relying more heavily on the seller’s personal knowledge transferring cleanly during a transition period than on anything durable in the firm itself. Weigh that finding against how long and how involved the seller is willing to be during handover, and price the risk accordingly rather than assuming it away.

• Written engagement scope and billing history checked against actual client records
• Confirmation the firm has no outstanding CRA remittance, payroll or GST/HST filing problems
• A full inventory of software accounts and logins, and who legally controls each one
• Whether client data-handling practices meet the firm’s privacy obligations
• How much of client retention realistically depends on the seller staying involved after closing
• A direct sample check of client books for currency and accuracy, not just documentation
• The firm’s track record processing remittances on clients’ behalf, and any past errors
• Employment or contractor classification for any staff beyond the owner

How long this diligence realistically takes

Diligence on a bookkeeping firm can move faster than on businesses carrying real estate or heavy equipment, since there is little in the way of physical assets to inspect — but confirming CRA standing and reviewing client-by-client documentation still takes real time, and rushing it is exactly how an undocumented client base gets discovered after closing instead of before.