Licensed Copilot is not the whole bill
People count seats and forget personal ChatGPT. That unofficial line is often larger, and it never shows up in the invoice meeting.
Invoice versus workflow
Most teams can name the AI invoice. Almost none can name which workflow created it.
If spend is small and one team owns it, a spreadsheet is enough. If several teams are in it and you cannot attribute 20% of the bill, the leak is explanation, not tokens.
One minute
Unattributed annual = monthly × (1 − attributed share) × 12. Leave it alone under $1,500 a month with one team.
The draft that shipped with no name on it
Nobody files a ticket for that. So it survives. That is the expensive leak.