Ten audits, around £750k recovered.
What a systematic audit programme returns when it is run as a discipline rather than as a response to a problem.
Audits were happening, but reactively: someone noticed something, someone looked into it. There was no standing programme, no consistent method, and no way of knowing whether the sites nobody had queried were clean or simply unexamined.
Line by line, back to source.
Vendor billing against contracted rates, on a fixed schedule rather than on suspicion
Whether the work invoiced matched the work evidenced on site
Compliance with the contract terms the client had actually negotiated
Recoverable amounts on audits across the programme, totalling around £750,000.
Recurring patterns rather than isolated errors, which meant the fix was procedural, not case-by-case.
Sites that had never been queried were not materially cleaner than the ones that had.
Auditing moved from reactive to scheduled, with a consistent method and a written finding for every item. The recovery was the visible result; the deterrent effect on future billing was the durable one.