B2B on Shopify Plus: lessons from a $40M migration

Last year I moved a $40M wholesale distributor from a 15-year-old ERP-driven workflow of phone orders, faxed purchase orders, and emailed spreadsheets onto Shopify Plus B2B. Nothing about it resembled a D2C build. Here is what I would tell anyone starting a similar migration.

B2B buyers optimise for speed, not discovery

A dealer ordering the same 60 SKUs every month does not want your mega-menu. They want a quick-order pad: paste the SKUs, see the contract prices, and submit. We built exactly that, and it became the single most-used page on the store, some 68% faster than the phone workflow it replaced.

Browsing and discovery still matter for new product lines, but the core flow should be designed around repeat purchasing. Your best B2B customers should be able to reorder in under a minute.

Pricing is the real migration

The storefront was the straightforward part. The difficult part was fifteen years of pricing logic: customer-specific contracts, volume breaks, regional lists, and handshake deals living in a sales representative's memory. Budget more time for pricing archaeology than for development. We spent six weeks simply reconciling what customers were genuinely paying against what the ERP said they should pay, and found six figures of margin leakage in the process.

The ERP will not meet you halfway

Legacy ERPs speak in nightly batch files, not webhooks. We built a middleware layer on Node.js, BullMQ, and PostgreSQL that translated between Shopify's real-time events and the ERP's batch world, with idempotent writes and a reconciliation loop that catches drift before the finance team does. That layer ran at 99.98% uptime and, critically, lost no orders during the cutover.

Cut over in phases, and keep the fax machine on

We ran both systems in parallel for eight weeks, moving dealers across in cohorts and starting with the friendliest accounts. The fax machine stayed plugged in until the final cohort had migrated. No one's fourth quarter is worth a big-bang cutover.

The result was order entry 68% faster, dealer onboarding three times quicker, and sales representatives working on account growth instead of data entry. B2B commerce is not glamorous; it is simply where the money is.