Source-to-pay explained: A guide for finance leaders

In many organisations, buying still happens in fragments. One team raises purchase requisitions using an enterprise resource planning (ERP) system. Another negotiates supplier contracts. Accounts payable manages invoice processing somewhere else while finance receives reports weeks later.

When procurement activities sit across disconnected systems, spend visibility drops, approval workflows slow down and supplier performance becomes harder to track. This leaves finance teams struggling to forecast cash flow, evaluate suppliers and identify where cost savings can be made.

To address this, finance leaders in the UK and beyond are increasingly turning to the source-to-pay (S2P) process so they can connect sourcing, purchasing and payments within a single system.

What is the source-to-pay process?

Source-to-pay is the end-to-end procurement framework that links supplier sourcing, purchasing and payment workflows across the supplier lifecycle.

The source-to-pay process covers everything from identifying potential suppliers and negotiating contract terms to issuing purchase orders, receiving goods and managing invoice payments.

By connecting these steps into a single workflow, you gain clearer oversight of supplier relationships, procurement activities and spend management. This visibility doesn’t just improve decision-making across the organisation. It also reduces time-consuming manual work, contributes to ensuring compliance and supports stronger risk management across the supply chain.

In practice, S2P helps your procurement teams move away from reactive buying and towards strategic sourcing and lifecycle management. As part of this transition, supplier selection and purchasing activity become more aligned with your organisation’s broader procurement strategy and growth goals.

The six steps of the source-to-pay process

A typical S2P process follows six connected stages that link sourcing, purchasing and payment.

1. Finding and evaluating suppliers

Procurement teams begin by identifying potential suppliers that meet the organisation’s requirements. This stage often includes the following tasks:

• Supplier evaluation

• Requests for information (RFIs)

• Requests for proposals (RFPs)

• Requests for quotations (RFQs)

• Supplier onboarding

• Supplier information validation.

The goal is to identify suppliers that can offer consistent quality, reliable delivery and competitive pricing. With strong, reliable suppliers, you build stable supply chains and lessen procurement risk.

2. Negotiating contracts

Once you’ve selected your suppliers, you define contract terms, pricing and delivery expectations. Effective contract negotiation and contract lifecycle management are essential to protect your commercial agreements and keep suppliers accountable.

3. Creating and approving purchase requisitions

Next, internal stakeholders submit purchase requisitions to request goods or services. These requisitions move through an approval workflow that ensures purchasing decisions align with procurement policies and budgets. With structured approvals, you reduce maverick spend.

4. Issuing purchase orders

Once approved, requests are converted into purchase orders, which formally confirm supplier agreements, quantities and price. The purchase order becomes the central document that links procurement, supplier fulfilment and finance.

5. Receiving goods and processing invoices

After delivery, you confirm receipt of goods and begin invoice processing. Your accounts payable team validates invoices against purchase orders and receipts before payment. This step confirms the invoice matches the purchase order and goods received, helping your finance team catch overbilling, duplicates or pricing errors before payment.

6. Analysing spend and supplier performance

Finally, you perform spend analysis and supplier performance management. This step reveals purchasing trends, contract compliance gaps and cost‑saving opportunities. With these insights, you can optimise procurement operations and improve forecasting for subsequent transactions.

Why focus on source-to-pay

Finance leaders are increasingly focusing on source-to-pay because fragmented procurement systems create financial blind spots and operational inefficiencies. When sourcing, purchasing and payments sit across different tools or departments, you lose visibility into how money moves through the organisation.

In implementing S2P, finance leaders are seeking to rectify the following:

• Limited spend visibility caused by siloed procurement systems. Ardent Partners’ CPO Rising 2025 report found that only 9% of organisations have fully automated spend analysis while 28% still rely on completely manual reporting. When data is disconnected, it’s difficult to see total spending across suppliers or categories.

• Slow purchasing and payment cycles due to manual approvals and disjointed workflows. This is particularly important, as Amazon Business’s 2025 State of Procurement Data report identified that 47% of decision-makers point to efficiency and complexity as their top procurement challenges.

• Unclear supplier performance due to information sitting across various contracts, procurement systems and finance platforms. This means it’s more difficult to track supplier reliability or enforce contract terms. According to the same Amazon Business report, 64% of decision-makers are tackling this issue by implementing improvements to data and insights.

A structured source-to-pay process addresses these problems by connecting sourcing, purchasing and payment activities within one workflow:

• Centralised purchasing data allows you to analyse supplier spending in real time and identify cost-saving opportunities

• Automated approvals and connected systems reduce manual steps, enabling purchase requisitions, purchase orders and invoices to progress through the procurement cycle more efficiently

• Shared supplier data makes it far easier to assess supplier reliability, enforce contract terms and manage supplier relationships across the supply chain.

Ultimately, S2P gives you the visibility and control you need to manage spend more effectively, mitigate risk across the supply chain and make more financially sound procurement decisions.

Challenges when starting with source-to-pay

Implementing a new S2P process can introduce challenges, particularly for organisations transitioning from manual procurement workflows or fragmented systems. Recognising these obstacles early helps you design more effective S2P implementation strategies.

Visibility gaps

Many organisations begin their source-to-pay journey without a unified source of procurement data. Supplier information may sit in spreadsheets, contracts in document systems and invoices inside accounting platforms.

Without integration, you’ll struggle to perform reliable spend analysis or supplier performance tracking. To close these visibility gaps, you need to connect your procurement, ERP and accounts payable systems.

Unclear roles or approval steps

Source-to-pay introduces structured procurement workflows that require clear ownership across departments. Without defined responsibilities for purchase requisitions, supplier onboarding or contract lifecycle management, approval processes can stall and cycle times can increase.

Establish clear approval hierarchies to ensure procurement activities move efficiently through the procurement cycle.

Supplier compliance

Supplier onboarding and supplier management become more complex as your organisation grows.

To keep suppliers aligned with your strategies, you need to track effectiveness, compliance requirements and contract terms across all your providers. Without a consistent evaluation approach in place, you’re more likely to face supplier disputes or procurement policy violations.

While all of these challenges are common during your switch to digital procurement, they are fixable. Better data visibility across procurement and clearer policy setting and implementation are your first steps to resolving them.

How Amazon Business helps with source-to-pay

Modern source-to-pay solutions centralise procurement activities and improve spend visibility. Amazon Business supports this shift by simplifying purchasing workflows and facilitating access to supplier information across the procurement lifecycle:

• Consolidated purchasing accounts allow organisations to bring fragmented buying activity into a single platform. This structure gives you clearer insights into purchasing patterns and supplier spending.

• Automated approval workflows enforce procurement policies before purchases occur. By guiding purchase requisitions and purchase orders through defined workflows, you maintain control over spending while decreasing the need for manual approvals.

• Invoicing capabilities further support your finance teams by connecting purchasing activity with invoice processing and accounts payable workflows. This alignment reduces manual reconciliation and accelerates payment processing.

• Real-time reporting gives you clearer spend visibility. When purchasing data sits in one platform, you can identify savings opportunities and evaluate supplier performance more efficiently.

This is why future-forward organisations choose Amazon Business. We use automation and data insights to help you streamline procurement operations while affording you stronger control across an integrated procurement workflow.

Grow with a connected source-to-pay process

Disconnected procurement systems create unnecessary complexity. When sourcing, purchasing and payment systems operate independently, finance teams lose visibility into supplier expenditure, contract commitments and operational risk.

The key to attaining this visibility and control is centralisation. A connected source-to-pay process brings these activities together into a single end-to-end workflow. With this structure, you can simplify the procurement process, strengthen supplier relationships and improve spend management across the supply chain lifecycle.

As an added benefit, this integrated approach brings clarity. When procurement data flows through a connected platform, you can make informed decisions about suppliers, costs and procurement strategy that feed positively into your organisation’s growth.

Get in touch today to find out how Amazon Business can help you streamline purchasing and keep prices and providers on track.

This article was created by professional writers and editors with the assistance of AI-powered tools. AI was used in a supportive capacity only – for example, to aid with translation, content review, and alignment with brand guidelines. All substantive research, editorial decisions, and final approval were performed exclusively by human authors and editors, who retain full editorial responsibility for this publication.