Source of Truth in B2B Commerce: ERP vs PIM vs OMS vs Ecommerce (Field-by-Field Guide)
A pragmatic ownership model for product, customer, pricing, inventory, and order data—so your integrations stop drifting, and ops stops firefighting.
February 4, 2026
If your team argues about “source of truth” every time something breaks, you’re not having an architecture debate—you’re living with an ownership model that was never made explicit.
In B2B commerce, ambiguity is expensive. It shows up as:
- customer-specific pricing that’s right in one system and wrong in another,
- inventory that looks available online but isn’t allocatable in the warehouse,
- orders that exist in ecommerce but never make it to the ERP,
- reconciliation work that quietly becomes someone’s full-time job.
This guide gives you a practical way to decide which system owns which fields, how to implement it without replatforming, and how to keep it from drifting again.
The only rule that matters: one field, one owner
Every data element that impacts a buyer decision (availability, price, lead time, payment terms) must have:
- a single system of record (owner),
- a defined propagation path (how it gets to other systems), and
- a validation/reconciliation rule (how you detect drift).
Everything else is implementation detail.
What each system is good at (and what it’s bad at)
ERP (System of record for commercial truth)
Best at:
- contract pricing logic and customer master data
- financial truth (invoices, credit, terms)
- fulfillment truth (shipments, allocations) when implemented cleanly
Bad at:
- rich content, merchandising, digital taxonomy
- “fast iteration” on storefront experiences
PIM (System of record for product content)
Best at:
- product attributes, taxonomy, enrichment workflows
- channel-specific content, governance, translation
Bad at:
- real-time inventory/availability
- contract pricing logic
OMS (System of record for order orchestration)
Best at:
- distributed order management, sourcing, split shipments
- promise dates and complex fulfillment routing
Bad at:
- long-term financial truth (you still invoice somewhere)
Ecommerce platform (System of record for digital experience)
Best at:
- buyer UX (search, PDP, checkout)
- catalog presentation and merchandising
Bad at:
- being the canonical owner of pricing/inventory in B2B (unless you intentionally design it that way)
Field-by-field ownership model (practical default)
Use this as a default starting point. There are exceptions, but you should be able to explain why you’re making them.
Product data
Own in PIM (or ERP if you don’t have PIM):
- marketing title, descriptions, images
- category/taxonomy, attributes, specs
- channel-specific naming and content rules
Own in ERP:
- SKU identifiers, UOMs, base item master
- pack/case rules (where they are operational)
Publish to ecommerce:
- “presentation” product objects (PDP-friendly) assembled from PIM + ERP
Customer & account data
Own in ERP/CRM (one of them must be canonical):
- customer master, ship-to, bill-to
- credit terms, tax exemptions
- customer segmentation and sales ownership
Mirror in ecommerce:
- accounts/roles for authentication
- buyer-specific catalog visibility rules (but don’t invent net-new truth here)
Pricing (the landmine)
Own in ERP (almost always in B2B):
- contract pricing
- customer-specific discounts
- price breaks / quantity tiers
- net price logic and rounding rules
Ecommerce should not “decide” B2B price—it should render price computed by the owner.
Implementation note:
- If you must do “price shaping” in ecommerce (promos, bundles), document it explicitly and keep it additive (never overriding base contract truth).
Inventory & availability
Break this into three concepts:
- On-hand (what exists)
- Allocatable / ATP (what you can promise)
- Availability messaging (what you show the buyer)
Own on-hand + allocation in ERP/WMS/OMS:
- warehouse truth (bins, lots, allocations)
Own promise logic in OMS (if present):
- multi-warehouse sourcing
- split shipment rules
- lead time rules and ship method constraints
Ecommerce owns messaging only:
- how you display “in stock / limited / backorder / call”
Orders & order status
Own order financial record in ERP:
- invoicing, payments/AR, final record
Own order orchestration in OMS (if present):
- holds, sourcing, splits
Ecommerce owns buyer UX:
- order placement experience
- self-service status views that reflect ERP/OMS truth
The anti-patterns that create drift
- Two masters: ERP and ecommerce both “own” pricing rules.
- Nightly batch roulette: critical data updated once/day with no reconciliation.
- Middleware as business logic: contract pricing rules buried in iPaaS transforms.
- No monitoring: you track “job ran” not “records reconciled.”
How to implement this without a replatform
Step 1 — Declare ownership in writing
Create a one-page “data ownership contract” with:
- field group
- owner system
- source → destination(s)
- update frequency/latency target
- validation/reconciliation method
Step 2 — Start with the two fields that cause the most pain
In most B2B orgs, it’s:
- pricing
- availability/ATP
Get those right and 60% of the firefighting disappears.
Step 3 — Add reconciliation before you add features
Pick 3–5 nightly checks:
- price drift: ERP vs ecommerce (by customer segment)
- inventory drift: allocatable vs ecommerce availability
- order flow: ecommerce orders that did not create ERP/OMS orders
Step 4 — Make “override paths” explicit
If sales reps can override price, define:
- where overrides are stored
- how long they last
- how they propagate
Internal links + next step
If you’re seeing drift and manual workarounds, the fastest win is a short architecture session to map your ownership model and implement 2–3 reconciliation monitors.
- Talk to an architect: /contact
- Integrations overview: /integrations
- Results/case studies: /results
CTA: Get a 30-day integration stabilization plan
If you want, we can run a lightweight integration audit and give you:
- a field-by-field ownership model,
- a prioritized remediation list,
- and the first monitoring checks so drift is caught early.
Start here: /contact