Your Finance Function Probably Has One Point of Failure
Most owners can name their operational key-person risks without hesitation. The estimator who prices everything. The site supervisor who holds the client relationships. The technician nobody else can replace.
The finance function rarely makes that list, and it's often the most concentrated risk in the business.
How it builds
A good bookkeeper joins when the business is smaller. They set things up their way, and their way works. Over five or six years they absorb every peculiarity the business generates — the client who pays in odd instalments, the supplier whose invoices never match the PO, the payroll import that fails unless a column is reformatted first, the two accounts that have to be reconciled by hand because of a conversion error in 2019.
They handle all of it. Nothing ever escalates, which is exactly why nobody looks.
Meanwhile they become the only person who knows the coding conventions, the only person with full system access, the only person who understands how the job costing report is actually assembled, and the only person who could explain why the balance sheet has the accounts it does.
This isn't a failure of the bookkeeper. In most cases it's a reflection of how well they've done the job. It's a failure of design — nobody ever specified that the finance function should be able to survive a change of personnel.
When it becomes real
Resignation. A four-week notice period is not enough to transfer five years of undocumented process. The successor spends their first quarter reverse-engineering the system rather than running it, and reporting quality drops through exactly the period when management most needs continuity.
Illness or extended absence. Worse than resignation, because there's no notice and no handover at all.
Growth. At some point the volume exceeds one person's capacity. Hiring a second person into an undocumented function is difficult — there's nothing to hand over, so the new person can't be productive, and the incumbent ends up doing their own job plus training.
Due diligence. This is the one that surprises people. A buyer or a lender will ask how the numbers are produced, who produces them, and what happens if that person leaves. "One person does all of it and nothing is written down" is a finding. It affects confidence, and confidence affects price.
What to put in place
None of this requires a project. It requires four artefacts.
A documented month-end process. Written by the person who does it, as a checklist rather than a manual. Each task, in order, with the system it's performed in and the evidence that it's complete. A single page is usually enough. The act of writing it also tends to surface two or three steps that turn out to be unnecessary.
An access register. Every system the finance function touches — accounting platform, payroll, banking, expense tools, supplier portals — with who has access, at what level, and who can grant it. Businesses frequently discover during this exercise that a former employee still has access to something.
A second competent pair of hands. Not a full backup, but someone who can run a pay cycle and complete a bank reconciliation without supervision. Rotating one task a quarter to a second person is enough to keep the knowledge live.
A quality standard. The most useful framing I've found: could a competent bookkeeper who has never seen this business pick up the file and understand it inside a day? If the answer is no, the reason is worth identifying — usually non-standard account names, undocumented conventions, or reconciliations that only make sense with verbal explanation.
The overlap with sale readiness
That last standard is also, almost word for word, the standard a buyer applies during diligence.
Books that a stranger can pick up are books that survive scrutiny. Books that depend on one person's explanation invite questions about what else depends on one person.
Fixing it costs a few days of documentation. Not fixing it costs you at exactly the moment you have least control over the timing.