(B2B) Business-to-Business Sites

Business-to-business ecommerce is the exchange of products, services, and information between companies rather than between a business and an individual consumer. It is the largest segment of online commerce by transaction volume, significantly exceeding the consumer retail market that receives most of the public attention. When a manufacturing company orders raw materials from a supplier, when a hospital system procures medical equipment from a distributor, when a retailer replenishes inventory through an automated purchase order system, or when a technology company renews a software license through a vendor portal — these are all B2B transactions. The websites that support them are built around fundamentally different requirements than consumer-facing storefronts, and the web developers who build them need to understand those differences in detail.

The most important structural difference between B2B and B2C ecommerce is the nature of the buying relationship. In B2C, the buyer is typically an anonymous individual making a one-time or infrequent purchase decision independently, often on impulse, with a credit card as the payment instrument. In B2B, the buyer is an organization operating through a defined procurement process that may involve multiple approvers, a purchase order workflow, a negotiated pricing agreement specific to that buyer's account, and payment terms that extend 30, 60, or 90 days after delivery. The B2B website must support all of these requirements — account-based pricing, approval workflows, purchase order generation, and net-term invoicing — which a standard B2C checkout flow does not address at all.

The primary goal of a B2B Internet site is to automate aspects of the supply chain in order to reduce processing time and eliminate the manual errors that paper-based procurement introduces. This automation spans the full procurement lifecycle: generating and submitting purchase orders, tracking order status in real time, managing inventory levels across multiple locations, coordinating shipping logistics with carriers, and confirming receipt of goods against the original order. Each of these functions was once handled through phone calls, fax transmissions, and paper documents that moved between departments and companies over days or weeks. A well-implemented B2B platform replaces that friction with computer-to-computer communication that operates continuously and at scale, compressing procurement cycles from days to hours and reducing the clerical labor required to manage supplier relationships.

Global B2B ecommerce exceeded $20 trillion in transaction value in 2023 and continues to grow across manufacturing, healthcare, logistics, financial services, and professional services. Digital procurement adoption is accelerating as businesses recognize that automated supply chain management reduces costs, improves order accuracy, and provides real-time visibility into purchasing activity that paper-based and phone-based systems cannot match. For web developers entering the enterprise software market, B2B platform development represents one of the most technically complex and commercially significant areas of ecommerce work available.

Supply Chain Automation

Supply chain automation is the defining functional characteristic of a B2B ecommerce site. Where a B2C site is built around the shopping experience — search, browse, add to cart, checkout — a B2B site is built around the procurement workflow, which begins before the buyer visits the site and continues long after the order is placed.

The procurement workflow in a B2B context typically begins with a purchase requisition generated internally by the buying organization — a department identifies a need, a requisition is submitted, and an approval chain validates the purchase against budget. Once approved, the requisition becomes a purchase order that is transmitted to the supplier. The supplier's system acknowledges receipt, confirms availability and pricing against the buyer's account-specific contract, and schedules fulfillment. As the order moves through the warehouse and shipping process, advance ship notices are transmitted back to the buyer's system so that receiving departments can prepare. When goods arrive, a goods receipt is recorded and matched against the original purchase order and the supplier's invoice in a three-way match process that is standard in enterprise accounting. Each of these steps generates a document that must be transmitted, acknowledged, and stored — and a B2B platform automates as many of these steps as possible to reduce cycle time and eliminate manual reconciliation errors.

For web developers, supply chain automation means building integration points between the ecommerce platform and the enterprise systems on both the buyer and supplier side — ERP systems, warehouse management systems, transportation management systems, and financial systems — rather than building a self-contained storefront. The platform is a node in a larger automated network, not an isolated application.

Payment in B2B Ecommerce

Electronic payment in B2B transactions has historically been managed through EDI — Electronic Data Interchange — a standardized format for computer-to-computer transfer of business documents including purchase orders, invoices, advance ship notices, and payment remittances. EDI was developed in the 1960s and 1970s to replace paper documents in high-volume trading relationships, and it remains the dominant standard for large-enterprise procurement automation today. EDI allows a company's procurement system to query a supplier's inventory system, generate a purchase order in a standardized format, and transmit it directly without human intervention, receiving an acknowledgment and eventually an invoice in return through the same automated channel.

Traditional EDI relied on value-added networks (VANs) — private networks operated by third-party providers that managed the transmission and routing of EDI documents between trading partners. VANs provided reliability and security but were expensive to connect to and required specialized technical expertise to operate. Large corporations could justify the cost because the transaction volume made the investment worthwhile, but mid-sized businesses often could not.

Modern B2B platforms have significantly expanded the options available for electronic procurement integration. REST API connections allow real-time data exchange between buyer and supplier systems using the same web-standard protocols that power consumer applications, making integration far more accessible to development teams without specialized EDI expertise. EDI-over-HTTPS and EDI-over-AS2 transmission standards have made traditional EDI documents transmittable over the public internet with security equivalent to VAN-based transmission, reducing the infrastructure cost for organizations that want to maintain EDI compatibility with large trading partners while avoiding VAN fees. Managed procurement platforms such as SAP Ariba, Coupa, and Oracle Procurement Cloud provide network environments where thousands of buyers and suppliers connect through a common platform, reducing the per-relationship integration burden because a supplier who connects to the platform once becomes accessible to all buyers on the network.

Payment settlement in B2B ecommerce also differs fundamentally from consumer transactions. Rather than real-time credit card authorization, B2B payment typically occurs on net terms — the buyer receives goods and submits payment 30, 60, or 90 days after the invoice date, depending on the negotiated terms of the trading relationship. Virtual card programs, ACH transfers, and supply chain financing platforms have modernized B2B payment settlement, but the underlying net-terms structure remains standard practice across most industries.

Security in B2B Ecommerce

Security is a foundational requirement of any B2B site because the data it handles is commercially sensitive in ways that consumer data is not. Purchase volumes, negotiated pricing agreements, supplier contracts, inventory levels, and demand forecasts are all competitively valuable information. A competitor who gains access to a company's supplier pricing knows the cost structure behind every product that company sells. A supplier whose customer order data is exposed loses the confidentiality that underpins its trading relationships. Exposure of this data — whether through a security breach, misconfigured access control, or intercepted transmission — can cause direct financial harm and permanently damage supplier relationships that took years to establish.

Network-level security is the first line of defense. Firewalls isolate the enterprise's internal systems from public internet access, placing the B2B platform in a network segment that is accessible to authenticated trading partners but not to the general public. Intrusion detection and prevention systems monitor network traffic for patterns associated with known attack methods and can block or alert on suspicious activity before it reaches the application layer.

Transport-layer encryption via TLS (Transport Layer Security) ensures that data in transit between buyer and supplier systems — purchase orders, invoices, pricing data, inventory queries — cannot be intercepted and read by a third party monitoring network traffic. This applies equally to API-based integrations, EDI-over-HTTPS transmissions, and browser-based user interactions with the procurement portal.

Identity and access management within the B2B platform must account for the organizational complexity of enterprise buying. A procurement manager may have authority to approve orders up to a certain dollar value but not above it. A department head may be able to view orders placed by their team but not by other departments. A supplier's account manager may have access to orders and invoices for their account but not to the buyer's contracts with other suppliers. OAuth 2.0 authentication and role-based access control (RBAC) provide the framework for implementing these constraints in a maintainable way. For enterprises operating in regulated industries — healthcare, financial services, defense — compliance frameworks such as SOC 2 Type II provide third-party verification that the security controls implemented on the platform meet defined standards, which is often a prerequisite for onboarding large institutional buyers.

In the next lesson, you will learn about the characteristics of business-to-consumer sites.