Source-to-Pay is the end-to-end process that covers everything from sourcing strategy and supplier selection through to paying for delivered goods and services. It’s broader than Procure-to-Pay — it extends upstream into strategic sourcing, supplier evaluation, and contract management, across the full lifecycle of a buyer’s commercial relationship with its suppliers.
What It Is #
Procure-to-Pay (P2P) starts at the point of an identified purchase need. Source-to-Pay starts earlier: at the strategic level of deciding which suppliers to work with, negotiating contracts, and setting the terms that govern every transaction that follows.
The decisions made at the sourcing stage — which suppliers to select, what payment terms to negotiate, what quality standards to require — determine the efficiency of every downstream P2P transaction. Strong sourcing sets the foundation for strong procurement.
For supply chain finance, this is where the important decisions happen. Payment terms, reverse factoring access, and dynamic discounting are all negotiated during supplier contracting, not at invoice approval.
The Full S2P Process #
Stage 1: Category Management and Spend Analysis #
Procurement teams analyse total spend by category, supplier, and geography, looking for opportunities to consolidate suppliers, leverage volume, and improve contract terms. Spend visibility is the starting point for any strategic sourcing initiative.
Stage 2: Market Analysis and Supplier Identification #
The market is assessed for potential suppliers. Existing suppliers are benchmarked against alternatives. New suppliers are identified and evaluated for capability, capacity, financial health, and compliance.
Stage 3: Request for Information (RFI) #
An RFI is sent to potential suppliers to gather information about capabilities, capacity, certifications, and financial stability. It collects facts without committing to a purchase.
Stage 4: Request for Proposal / Quotation (RFP / RFQ) #
Shortlisted suppliers submit formal proposals or price quotations. Evaluation criteria typically include price, quality, lead times, payment terms, sustainability credentials, and service levels.
Stage 5: Supplier Evaluation and Selection #
Proposals are scored against weighted criteria. The winning supplier is selected and negotiations begin on final terms — payment terms, volume commitments, quality standards, and any SCF programme participation.
Stage 6: Contract Management #
Contracts are finalised and signed. Payment terms are documented. SCF programme terms — reverse factoring access, dynamic discounting eligibility, early payment discount structures — are agreed and embedded in the contract.
Stage 7: Procure-to-Pay Execution #
The P2P cycle runs against the contracted terms: PO issuance, goods receipt, invoice processing, approval, and payment.
Stage 8: Supplier Performance Management #
Ongoing monitoring of supplier performance against contracted KPIs. Regular reviews assess quality, delivery, compliance, and relationship health. Performance data feeds back into future sourcing decisions.
S2P vs. P2P #
| Dimension | Source-to-Pay (S2P) | Procure-to-Pay (P2P) |
|---|---|---|
| Scope | Sourcing strategy through payment | Purchase need through payment |
| Starts at | Market analysis and supplier strategy | Identified purchase requirement |
| Includes strategic sourcing | Yes | No |
| Includes contract management | Yes | Partially |
| Key stakeholders | CPO, category managers, finance, legal | AP team, procurement operations, treasury |
| Technology | S2P suites (Coupa, Jaggaer, SAP Ariba) | ERP, AP automation, SCF platform |
| SCF touchpoint | Payment terms negotiated at contract stage | Early payment execution at invoice stage |
Where SCF Connects to S2P #
Supply chain finance integrates into the S2P process at two critical points:
Contract stage (Stage 6). Payment terms — including DPO targets, early payment discount structures, and reverse factoring programme access — are agreed with suppliers as part of contract negotiations. Procurement teams can offer SCF programme access as a value-add that makes extended payment terms more acceptable to suppliers.
P2P execution (Stage 7). Approved invoices flow into the SCF platform automatically via API, triggering early payment notifications to suppliers and DPO management for the buyer.
Strategic Sourcing and SCF as a Negotiation Tool #
Supply chain finance is an underused tool in sourcing negotiations. Buyers who offer reverse factoring programme access during supplier negotiations can:
- Negotiate longer payment terms. Suppliers accept 90-day terms more readily when early payment is available.
- Achieve better pricing. Suppliers with access to low-cost early payment have lower financing costs and can pass savings through in their pricing.
- Attract higher-quality suppliers. Premium suppliers prioritise buyers who offer financial stability programmes.
- Reduce supplier risk. Financially healthy suppliers, supported by SCF access, are less likely to fail, cut quality corners, or exit the relationship.
Key S2P Metrics #
| Metric | Definition | Target |
|---|---|---|
| Supplier Onboarding Time | Days from selection to first transaction | Under 10 days |
| Contract Compliance Rate | % of spend under active contract | 85%+ |
| Competitive Sourcing Rate | % of spend subject to competitive tender | 70%+ |
| Supplier Concentration Risk | % of spend with top 5 suppliers | Under 40% |
| SCF Programme Adoption | % of eligible suppliers enrolled in early payment programme | 60%+ |
| DPO at Contract | Average payment terms negotiated | 60–90 days (with SCF) |