What an invoice audit finds, and what it cannot

An invoice audit is a comparison, not an investigation. Each line on the invoice is read against the signed contract for the period billed, and the arithmetic is recalculated rather than accepted. Where the charge depends on a figure held elsewhere, such as the agreed capacity for the supply or a meter reading, that figure is checked too.

That is the whole method. It is unglamorous, and it is why the errors it finds tend to be small, repeated and long-standing rather than dramatic.

An audit cannot find an error the invoices and the contract do not show. Where the only record sits with the supplier or the network operator, it has to be requested, and that takes as long as they take.

It cannot tell you whether the rate you signed was competitive on the day you signed it. That is a procurement question, answered by testing the market at renewal, not by reading a bill.

It cannot recover money outside the period a supplier will reopen, and that period differs by supplier, by charge type and by the reason for the error.

It cannot make correctly billed consumption disappear. Plant running through closed hours is a real cost, correctly charged. Reducing it is separate work with its own costs and payback.

Some accounts are billed correctly. Where that is what the read shows, that is what we report. A clean result is a useful result: it tells you the billing is not where your cost is, and points the work at consumption or at the next renewal instead.

Where data is missing, the gap is recorded as a gap. We do not estimate around a missing reading to make an invoice reconcile, because an invoice that has been made to balance is not the same as an invoice that has been checked.