P2P procurement is short for procure to pay, and it names the whole cycle from somebody deciding they need something to the supplier being paid for it. It is one process on paper and two departments in practice, and most of what people find frustrating about it happens at the boundary between them rather than inside either half.
What it covers
The requisition and its approval, the purchase order and its issue, the delivery and its receipt, the supplier invoice, the match, the invoice approval and the payment. Sourcing and supplier selection sit outside it, in what is usually called source to pay, and so does anything about the accounting treatment of what was bought.
Who owns which part
Purchasing owns the front half through to issuing the order. Payables owns the back half from the invoice onwards. The goods receipt sits in the middle and, in most organisations, is performed by operational staff who report to neither. That orphan step is the single most common source of problems in the whole cycle.
Why it is discussed as one thing
Because the quality of the front half determines the workload of the back half. An invoice arriving with an order and a receipt behind it is cheap; one arriving with neither is expensive. Treating the two halves as separate processes is what allows that dependency to go unmanaged for years.
Questions people ask about what is p2p procurement
Is p2p the same as purchase to pay?
Yes. Different vendors and textbooks prefer different phrasings and no distinction should be inferred.
Does p2p include sourcing?
No. Sourcing, tendering and contracting sit in the wider source to pay scope.
What is the single most useful measure?
The share of invoices arriving with both an order and a recorded receipt. It describes the health of the whole cycle in one number.