The procurement process, step by step: from need to payment

Process & tools · By the Buyer's Ledger editorial team · Published 2026-10-03

A person in green trousers and brown shoes climbing grey concrete stairs with bright yellow edges, seen from behind at step level — Climbing a staircase one step at a time. A procurement process runs the same way, from the first need to the final payment.

Every organisation buys things, but the steps between "we need this" and "the supplier has been paid" are often invisible until something goes wrong: an invoice without a purchase order, a contract nobody can find, a supplier chosen without competition. This guide walks through the full cycle, explains the two halves usually called source-to-contract and procure-to-pay, and flags the controls that matter at each step.

Two halves of one process

It helps to split the cycle in two. Source-to-contract (strategic sourcing) covers understanding the need, analysing the market, choosing a supplier and agreeing a contract. It happens relatively rarely for a given category and is where most value is created or lost. Procure-to-pay (P2P, sometimes called purchase-to-pay) covers the repeated operational steps of requisitioning, ordering, receiving, matching invoices and paying. It happens constantly and is where efficiency and control matter most. Together they are often called source-to-pay (S2P).

Step 1: Identify and validate the need

A requirement starts with a business user: a production planner who needs material, an IT team that needs software licences, a facilities manager who needs cleaning services. Before buying anything, two questions should be asked. Is the need real and correctly sized (could existing stock, an existing contract or a different approach meet it)? And is there budget? Many organisations formalise this as a purchase requisition routed for approval according to a delegation-of-authority matrix that sets who can approve how much.

Step 2: Define the requirement

The specification describes what is to be bought. There are two broad styles. A technical (conformance) specification describes exactly what the item must be: dimensions, materials, standards. An output or performance specification describes what the item or service must achieve and leaves the supplier freedom on how. Output specifications encourage innovation but are harder to evaluate; conformance specifications make comparison easy but lock in a solution. Whatever the style, the specification should avoid naming a brand unless genuinely necessary, since that eliminates competition before it starts.

Step 3: Analyse the market and choose a sourcing route

How many suppliers could meet the need? How concentrated is the market? What drives price? The answers determine the route: a quick comparison of quotes for a low-value standard item; a formal tender for a significant or complex purchase; a direct negotiation where only one supplier is credible; or a call-off from an existing framework agreement. Public bodies must follow their procurement law at this point (in the UK, the Procurement Act 2023; in the EU, Directive 2014/24/EU as transposed nationally). Private organisations set their own thresholds in internal policy.

The category management guide explains how to position a purchase by value and supply risk to choose a strategy.

Step 4: Go to market

Depending on the route, the buyer issues a request for information, proposal or quotation. The differences are covered in RFI vs RFP vs RFQ. Good practice is to publish evaluation criteria and their weightings with the request, give all bidders the same information at the same time, and log clarification questions and answers so that everyone sees them.

Step 5: Evaluate and select

Offers are scored against the published criteria. Price should be assessed on a whole-life basis where relevant (see total cost of ownership), and quality through the evidence bidders provide, references, site visits or samples. Due diligence checks the selected supplier's financial standing, insurance, compliance (sanctions screening, anti-bribery, data protection) and, increasingly, environmental and human-rights risks. Evaluation should be done by more than one person, with conflicts of interest declared and recorded.

Step 6: Negotiate and contract

Negotiation can refine price, payment terms, service levels, liability and other terms (see negotiation basics). The resulting contract should cover at least scope and specification, price and price adjustment, delivery terms (including Incoterms for goods moving internationally), service levels and remedies, liability and insurance, intellectual property, confidentiality and data protection, termination and dispute resolution. Store the signed contract in a single repository with its key dates (renewal, notice period, price review), because missed notice periods are one of the most common and avoidable sources of leakage.

Step 7: Order

A purchase order (PO) is the formal instruction to the supplier, referencing the contract, quantities, prices and delivery dates. For frequent low-value purchases, catalogues or purchasing cards reduce effort; for recurring supplies, blanket or scheduled orders release quantities against an agreed total. A firm rule of "no PO, no pay" is the simplest way to stop spending that bypasses contracts and approval.

Step 8: Receive and accept

When goods arrive or a service is delivered, someone confirms it: a goods receipt in the warehouse system or a service acceptance by the user. Inspection may check quantity, condition and conformity to specification. This record is what later proves that the organisation got what it is paying for.

Step 9: Match the invoice and pay

Accounts payable compares the supplier's invoice with the purchase order and the receipt. Agreement of all three on quantity and price is called a three-way match; a two-way match (PO and invoice only) is common for services or low-risk items. Discrepancies are routed back for resolution before payment. Payment is then made on the contractual terms. Paying on time matters: late payment damages supplier relationships, and in many jurisdictions it is regulated (the EU Late Payment Directive 2011/7/EU sets default rules for commercial transactions).

The legal maximums in the EU, France and the UK, and how to set terms your process can keep, are set out in our guide to supplier payment terms.

Step 10: Manage the supplier and the contract

The cycle does not end at payment. Performance is measured against agreed KPIs (see supplier evaluation scorecards), issues are escalated and resolved, risks are monitored (see supplier risk and resilience), and the contract is reviewed before renewal so that the next sourcing decision starts with evidence. Spend data from P2P feeds back into spend analysis, which identifies the next categories to source.

Controls that matter most

Risk	Control
Purchasing without approval or budget	Requisition approval by delegation of authority; budget check
Favouritism or corruption in selection	Competition thresholds, published criteria, panel evaluation, conflict-of-interest declarations
Spending outside contracts ("maverick" spend)	Catalogues, preferred suppliers, "no PO, no pay"
Paying for goods not received	Goods receipt and three-way match
Fictitious or duplicate suppliers	Segregation of duties between supplier creation, ordering and payment; bank-detail verification
Missed renewals and price reviews	Central contract repository with dated alerts

Professional bodies describe the cycle in slightly different words: the Chartered Institute of Procurement & Supply teaches a widely used procurement and supply cycle, and the Institute for Supply Management offers comparable frameworks. The labels vary; the logic of need, market, contract, delivery and review does not.

The cycle also maps onto private purchases, as our real-estate version of the purchasing checklist shows, from defining the need and analysing the market to managing the contract after signature.