ERP and e-commerce integration

What needs to stay in sync

• Inventory: the availability shown in the store must reflect real stock levels in real time or close to it, otherwise you sell products you don't have.
• Pricing: price lists, customer specific discounts, volume pricing, time limited promotions.
• Orders: every order placed online needs to flow into the ERP for invoicing, fulfillment, and accounting, without manual re-entry.
• Customer records: contact details, payment terms, purchase history, especially in B2B contexts with business accounts.

Three technical approaches

• Off the shelf connector: a market module, often provided by the ERP vendor or a third party, that covers standard cases. Fast to set up, but rigid once your business logic goes beyond what it expects.
• Middleware: a dedicated intermediate layer that orchestrates the data exchange, manages queues, and handles error recovery. More robust for high volume flows or complex business rules.
• Custom API: direct development between the e-commerce platform and the ERP, with no intermediate layer. A good fit when both systems expose clean APIs and the flows stay manageable in house or with a vendor.

How to scope the project

• List the objects to synchronize (inventory, pricing, orders, customers) and the direction of each flow: ERP to store, store to ERP, or both.
• Define the acceptable delay per flow: inventory rarely tolerates a multi hour lag, a customer record often can.
• Plan for error handling and duplicate detection before the first production run, not after the first incident.
• Budget for ongoing maintenance of the flow, not just the initial build. This scoping work is typically part of a custom e-commerce and B2B project.

Common pitfalls

Three mistakes come up repeatedly. Synchronizing too many objects from day one, which makes testing harder and delays the launch. Ignoring conflict handling, when the same record gets updated on both sides at the same time. And underestimating edge cases: temporary stockouts, customer specific negotiated discounts, returns and credit notes. On B2B projects with business accounts and per customer terms, this scoping overlaps with the work covered in business process automation.