Briefing
Sampling supplier invoices in a Malaysian mid-market AP team
A useful sample is not a random handful of PDFs. It is a plan that covers vendors, amounts, tax treatments, and the messy invoices nobody puts in a demo.
Start from the population you can defend
We ask for the list of invoices posted in a defined period, for named entities, including cancelled and reversed items. If cancelled items are missing from the export, the population is already incomplete. That is recorded before a single invoice is opened.
From that list we stratify: high value, new vendors, foreign currency, invoices without a PO, invoices posted near period-end, and a slice of ordinary local bills. Ordinary bills matter. Fraud and error both hide in routine.
Sit with the morning queue
In Ipoh and on client sites we still spend a morning watching the live queue. Sampling from a file will not show you a shared login, a stack of invoices approved from a phone in a corridor, or a clerk who knows which vendor master ‘just works’. Those observations belong in the letter alongside the sample results.