Can I build B2B on Magento Open Source without Adobe Commerce?

Yes, but expect a significant build cost. Open Source ships the core e-commerce engine but no B2B features, so you’re building (or buying) custom modules for companies + roles, quote workflow, customer-specific pricing, requisition lists, payment on account, and shared catalogues. Community modules exist (Mageplaza, Amasty, MGS) but they patchwork rather than integrate as one cohesive B2B model.

Our recommendation: if your annual B2B GMV is > $1M, Adobe Commerce pays for itself in fewer custom modules, faster build, fewer integration bugs, and Adobe support. Below $1M, an Open Source + 3-4 well-chosen B2B modules can work, we audit both routes in the discovery call.