B2B accounts payable automation is described as though it were entirely within your control, and roughly half of it is not. How an invoice arrives, in what format, with what reference and whether it carries a purchase order number are all decisions your supplier makes. A great deal of the exception rate that automation is meant to reduce is created by those decisions, and no amount of capture technology fully compensates for an invoice that does not quote the order it relates to. This page is about the supplier side: what you can change by asking, what needs leverage, and what to do when you have none.
What changes just by asking
Emailing PDFs to a single address rather than posting paper, quoting your purchase order number, and sending to the right address rather than to an individual. Most suppliers will do all three if asked once, clearly, and almost nobody asks.
What needs leverage
Structured formats, portal submission and standardised line detail. These cost the supplier something, so they happen where you are a significant customer and not otherwise. Insisting without leverage produces compliance from the willing and friction with everyone else.
What to do with the long tail
Accept that a proportion of invoices will arrive awkwardly and design the exception path for them rather than pretending they will stop. On the worked example on this site, 400 invoices at three touches of six minutes with a 12% exception rate is 134.4 hours a month: $4,300.80 at a $32 loaded rate, $10.75 an invoice and $51,609.60 a year. and the exception hours are largely this tail.
Questions people ask about b2b accounts payable automation
Should we mandate a supplier portal?
Only with the leverage to make it stick. A portal used by your ten largest suppliers and ignored by the other forty gives you two intake channels to watch.
Do e-invoicing standards help?
Where they are mandated or widely adopted in your market, considerably. Where they are not, adoption is the obstacle rather than the technology.
What is the highest-return ask?
The purchase order number on the invoice. It removes more matching exceptions per unit of effort than anything else you can request.