Integration is where payables projects overrun, because the number of possible connections is large and the number of necessary ones is small. Three connections carry almost all the value, and they are the same three in nearly every organisation. Being clear about which are necessary and which are conveniences is the difference between an implementation that lands and one that is still being configured a year later.
Connection one: purchase orders and receipts
Without the order and the goods receipt, there is nothing to match against, so this is the connection that makes automation possible at all. If your orders live in a separate system, getting them and their receipts into the payables tool reliably is the first job and the one worth spending implementation effort on.
Connection two: the general ledger
Approved, coded invoices have to reach the accounting system without rekeying, or you have automated the front half and left a manual step at the end. This connection usually determines what coding structure the payables tool must understand, so it shapes configuration more than any other.
Connection three: payment
Whether that is a banking file, a payment provider or a card programme, the approved invoice eventually has to become money leaving. This is where fraud controls matter most: changes to supplier bank details deserve verification outside the channel the change arrived on, whatever the software does.
Questions people ask about integrated accounts payable system
Do we need integration on day one?
The order and receipt feed usually yes, because it enables matching. The others can often follow, and staging them reduces the risk of a long implementation.
What if our purchase orders live in spreadsheets?
Then that is the first thing to fix, because no payables product can match against something it cannot see. This is a process decision before it is a software one.
How do we protect against supplier bank detail fraud?
Verify changes through a channel you already hold for that supplier, not one supplied in the request, and keep the verification on the record. This is a control, not a feature.