Every B2B eCommerce project that gets into trouble has the same root cause, and it is almost never the storefront. It is the connection between the store and the ERP. Your ERP (enterprise resource planning) system is the system of record for inventory, pricing, customers, and orders. If the website and the ERP disagree, customers see the disagreement: oversold stock, wrong contract pricing, orders that never reach the warehouse. Getting that integration right is the difference between web ordering that is as reliable as a phone call and a second system your team has to babysit.
This guide is platform by platform. We cover the six ERP systems we integrate with most for mid-market manufacturers and distributors, what is distinctive about connecting each one to a Magento, Adobe Commerce, or Shopware store, and the integration patterns that hold up under real B2B load. For the conceptual foundation behind all of it, start with our guide to eCommerce ERP integration.
What ERP integration actually does
At its core, integration keeps four data domains in agreement between the store and the ERP. The mistake most teams make is treating all four the same. They do not need the same speed, and forcing everything into real-time, or batching everything overnight, is how integrations get expensive or unreliable. Match the sync model to the data:
| Data domain | Direction | Sync model | Why |
|---|---|---|---|
| Inventory / stock | ERP → store | Near real-time | Stale counts cause oversells and support tickets |
| Pricing (incl. contract / tiered) | ERP → store | Near real-time or on-request | B2B pricing is account-specific and changes often |
| Orders | Store → ERP | Near real-time | Orders must reach fulfillment without manual rekeying |
| Order & shipment status | ERP → store | Near real-time | Customers and CSRs check status constantly |
| Customers / accounts | Bidirectional | Scheduled or event-based | Account hierarchies and terms live in the ERP |
| Product / catalog data | ERP → store | Scheduled | Large catalogs tolerate batch; reconcile for quality |
ERP integration, platform by platform
The integration interface, not the brand name, determines how the build goes. Here is how the six systems we see most differ, and where each one tends to get hard.
1. NetSuite
NetSuite is the most common ERP we meet in cloud-first, mid-market eCommerce. It exposes SuiteTalk (SOAP and REST) plus SuiteScript for custom logic, so most data you need is reachable through a documented API. The work is rarely about access and almost always about governance: NetSuite enforces API concurrency and usage limits, so a naive integration that hammers it during a catalog sync will get throttled. The reliable pattern is event-driven order and inventory sync through middleware that respects those limits, with catalog and customer data on a schedule.
2. SAP
SAP (ECC or S/4HANA) is where enterprise B2B complexity concentrates: multi-manufacturer sourcing, plant and company-code structures, and order logic that lives in the ERP rather than the store. Integration here is less about moving fields and more about respecting business rules SAP already enforces. For Magento storefronts specifically, see our Magento + SAP integration deep dive.
We built exactly this for Rifle Paper Co., a DTC brand sourcing from multiple manufacturers. SAP applies product sourcing rules automatically: when a customer orders items from three different manufacturers, SAP splits the order into three manufacturing requests, each sent to the right manufacturer in their required format. That logic stays in SAP, where it belongs, and the store simply hands off clean orders. The result is an order flow that holds together during peak season instead of breaking under manual routing.
3. Microsoft Dynamics 365
Dynamics spans two very different products: Business Central (mid-market) and Finance & Operations (enterprise). Both offer modern REST and OData endpoints, which makes Dynamics one of the friendlier ERPs to connect on paper. The real work is in the data model: Dynamics dimensions, customer hierarchies, and pricing agreements need to map cleanly to how your store represents customer groups and catalog price rules. Get that mapping wrong and you get pricing drift that is hard to trace later.
4. Acumatica
Acumatica is cloud-native and genuinely API-first, with a well-structured REST contract-based API. For distributors who chose Acumatica recently, it is often the smoothest integration of the six because the data is already designed to be accessed programmatically. The focus shifts to designing the right events (what triggers a sync, and in which direction) and to inventory accuracy across multiple warehouses, which is where distribution buyers feel the most pain.
5. Sage
Sage is not one product, it is a family: Sage 100, Sage 300, Sage X3, and Sage Intacct each have different integration surfaces, and the right approach depends entirely on which one you run. Older on-premise Sage installs often have no clean API at all, which makes a middleware or integration-bridge approach the practical path rather than a direct connection. The first question on any Sage project is always which Sage, because it changes the architecture completely.
6. Epicor (Prophet 21)
Epicor, and Prophet 21 (P21) in particular, is the ERP of serious distribution. It carries deep distribution logic: complex pricing matrices, contract pricing, units of measure, and warehouse rules that are the entire point of the business. Integration is not about exposing P21, it is about reproducing its pricing and availability faithfully on the web so a contractor ordering online gets the exact same number they would get on the phone. That fidelity, not raw connectivity, is the hard part.
A quick reference
| ERP | Typical buyer | Primary interface | Where it gets hard |
|---|---|---|---|
| NetSuite | Cloud-first mid-market | SuiteTalk REST/SOAP, SuiteScript | API governance / rate limits |
| SAP | Enterprise B2B & DTC | BAPI / IDoc / OData (S/4HANA) | Business rules & order splitting |
| Dynamics 365 | Mid-market to enterprise | REST / OData | Data-model & pricing mapping |
| Acumatica | Cloud-native distributors | Contract-based REST API | Event design, multi-warehouse stock |
| Sage | Varies by product line | Depends on Sage 100/300/X3/Intacct | No clean API on older installs |
| Epicor / P21 | Distribution | P21 API / middleware | Reproducing pricing fidelity |
The patterns that separate reliable integrations from fragile ones
Across every platform above, the same engineering decisions decide whether an integration lasts. These are the ones that matter.
- Bidirectional sync, not one-way export. The store and ERP should agree continuously, in both directions. For Lighting Supply, a 500,000-SKU lighting distributor, a well-engineered integration bridge (eBridge Connections) created continuous two-way sync so contractors got digital ordering while operations got their time back, instead of a nightly file that was already stale by 9am.
- An enforced pricing hierarchy. B2B pricing is layered, and the layers must resolve in a defined order. For Transcat, the rule is strict: customer-group pricing applies first, volume tiers override it, negotiated rates override tiers, and promotions never stack across all three. The system prevents unprofitable combinations from ever executing, rather than catching them after the fact.
- Pricing computed at the moment of browsing. For M.E. Campbell, an industrial and electrical distributor, account-specific pricing is calculated dynamically as customers browse, with real-time inventory across every warehouse. The customer never sees a list price they are not actually entitled to.
- Automated reconciliation, not reactive firefighting. At 500,000 SKUs, data quality degrades silently. Reconciliation scripts that flag products missing images, wrong pricing, or disconnected attributes let the team fix issues systematically from a report, instead of hunting for problems after a customer finds them.
- Middleware or iPaaS where it earns its place. A direct API connection is cleanest when the ERP has a good API. When it does not (older Sage, some Epicor installs), an integration platform absorbs the mismatch and the retry logic. The choice should be deliberate, not a default.
How to choose an ERP integration partner
ERP integration is the part of a B2B build with the least margin for error, so the partner you choose matters more here than almost anywhere else. What to look for:
- Named experience with your specific ERP. “We integrate ERPs” is not the same as having shipped NetSuite, SAP, or P21. Ask which systems, and ask to see the work.
- They lead with your business rules, not their connector. The first conversation should be about your pricing tiers, sourcing logic, and warehouse structure, not a product demo.
- They design the sync model per data domain. If everything is “real-time” or everything is “nightly,” they have not thought about it.
- They plan for reconciliation and failure from day one. What happens when the ERP is down? When a record fails to sync? Good partners answer this unprompted.
- They can show B2B results, not just storefronts. The proof is in distributors and manufacturers running on the integration, not in pretty homepages.
Proof: real B2B ERP integrations
We have built ERP-integrated commerce for manufacturers and distributors across NetSuite, SAP, Microsoft Dynamics, Acumatica, Sage, and Epicor. A few that show the range:
- Lighting Supply – 500,000-SKU bidirectional integration between modern eCommerce and a legacy ERP.
- Rifle Paper Co. – SAP integration with automated multi-manufacturer order splitting for enterprise DTC.
- Transcat – B2B industrial eCommerce with an enforced multi-tier pricing hierarchy tied to the ERP.
- M.E. Campbell – real-time, account-specific pricing calculated as customers browse, across every warehouse.
Start with the integration, not the storefront
The storefront is the easy part. The integration is what determines whether your B2B commerce is reliable enough to move real revenue through. If you are evaluating how to connect your ERP to Magento, Adobe Commerce, or Shopware, or an existing integration is causing more problems than it solves, let’s talk. We will start with your pricing, sourcing, and warehouse logic, and design the integration around how your business actually runs.
Cloud-native, API-first systems like Acumatica and NetSuite are generally the most straightforward because their data is designed to be accessed programmatically. The harder cases are older on-premise installs (some Sage and Epicor versions) that may lack a clean API and need a middleware or integration-bridge approach. The ERP brand matters less than the integration interface it exposes.
It depends on the data. Inventory, orders, and order status should be near real-time because staleness causes oversells and support tickets. Large catalog and product data usually tolerate scheduled batch syncs with automated reconciliation. Forcing everything into real-time is expensive, and batching everything overnight makes the store unreliable. Match the sync model to each data domain.
With an enforced pricing hierarchy. Customer-group pricing applies first, volume tiers override it, negotiated contract rates override tiers, and promotions are prevented from stacking in ways that create unprofitable prices. The hierarchy is enforced by the system so the price a customer sees online matches exactly what they are entitled to in the ERP.
Yes. A well-engineered integration bridge creates continuous bidirectional sync between a legacy ERP and a modern store, so the two work together rather than against each other. We have done this at 500,000-SKU scale, where contractors get digital self-service ordering and the operations team stops doing manual reconciliation.
It varies with the ERP, the number of data domains, and how much business logic lives in the ERP versus the store. The biggest driver is not the connection itself but the rules around pricing, sourcing, and warehousing that need to be reproduced faithfully. A scoping conversation about those rules gives a far more accurate timeline than any generic estimate.