The distribution of effort in payables surprises people who have not done it. Most invoices take almost no time: they arrive, match, get approved and are paid. A minority consume most of the day, and they are the same minority every month, with the same handful of causes. Understanding that shape is what stops improvement efforts being aimed at the wrong place.
The invoices that take no time
An order exists, a receipt was recorded, the invoice agrees within tolerance, and the approver responds. These can clear with barely any human attention, and in a healthy process they are the majority by count. Improving how they are handled produces little, because there is little there to improve.
The invoices that take all day
No purchase order, so somebody has to establish what it was for and who authorised it. No goods receipt, so nobody can confirm delivery. A price difference that requires purchasing to remember a conversation. A supplier nobody recognises. Each of these is a research task rather than a processing task, and each is generated outside payables.
Where that leaves improvement effort
Aimed upstream, at purchase-order coverage and receipt discipline, and at the exception routing that determines how long each hard invoice takes. Capture and keying improvements act on the invoices that were already cheap. That is not an argument against them, but it is an argument for measuring where your time goes before deciding.
Questions people ask about invoice accounts payable
How do we find out where the time goes?
Record, for one week, how long each invoice took and which category it fell into. A week of that data reorders most improvement plans.
Is it worth chasing small differences?
Below your tolerance, no, which is what tolerance is for. Above it, the question is whether the reason is systematic, since a repeated small difference is usually a pricing problem worth fixing once.
Should payables chase purchase orders?
Payables notices the absence; purchasing owns the behaviour. Reporting the count by department is usually more effective than payables chasing individuals.