Shadow AI in the finance department
The tools your staff use unofficially are usually harmless. There is one department where they are not, and it is the one nobody checks.
Unofficial tool use is normal and mostly benign. Somebody uses a free assistant to rewrite a supplier email; nothing of consequence happens. There is one exception, and it concentrates in a single department.
Why finance is different
Because the documents that pass through it are the ones you would least like to see elsewhere: the payroll run, the bank reconciliation, the draft annual accounts, the list of outstanding debtors, the salary bands.
And because finance work has a specific shape that invites unofficial tools. It involves tedious reformatting, comparing two lists, explaining a variance, tidying a spreadsheet. All of that is exactly what a free online assistant appears to be good at, and the person doing it at nine in the evening in January is not thinking about data governance.
What tends to happen in practice
Not a leak in the dramatic sense. What happens is that a spreadsheet extract with real figures and real names gets pasted into a consumer tool with consumer terms, once, and nothing visible follows.
The problem is not the single event. It is that nobody knows it happened, so it is not in the record the 28 October post recommended, and it will therefore be the one thing you cannot answer honestly if a customer or an auditor asks what has been processed where.
What to do, which is not a ban
A ban fails here for the reason bans usually fail: the work is tedious and the tool helps.
Two things work better. Give the finance team an approved tool with a business contract and make sure it is genuinely convenient — the one-click-too-far problem from 14 August is most acute where the work is most tedious. And name the three document types that never go anywhere unapproved, specifically: payroll, bank data, anything with individual salaries.
Why now
Because December and January are when this happens. Year-end close, annual accounts, salary reviews, everything late and everything tedious.
A five-minute conversation with your finance lead this week is worth considerably more than the same conversation in February, after the fact.