Every order placed on your online shop triggers a chain of operations inside your ERP: purchase order creation, stock update, invoice generation, accounting entry, and potentially a return. Without an integration between the two systems, this process runs on manual effort — and that is where margin disappears.
In 2026, three e-commerce platforms dominate the SME and mid-market space in Europe and beyond: Shopify, WooCommerce (WordPress) and PrestaShop. Rising fast, Shopware 6 is gaining ground in Germany and the DACH region. This guide covers which data flows to synchronise, which integration architectures to choose, which connectors are available per platform, and the seven classic pitfalls to avoid.
Why integrate your ERP and your e-commerce platform in 2026?
The real cost of manual re-entry
Consider an SME processing 80 online orders per day. Without integration, every order must be re-keyed into the ERP: customer reference, order lines, quantities, applied prices, discounts, payment method, shipping address. An experienced operator typically spends 3 to 7 minutes per order on this task. Over a 22-working-day month, that adds up to between 88 and 205 hours lost — the equivalent of 2 to 5 operator-weeks every single month.
That calculation does not include errors. Manual entry inevitably produces misallocated orders, stock discrepancies and invoices with incorrect VAT references. Each error costs time to correct, delays deliveries and can escalate into customer disputes.
ERP–e-commerce integration automates this entire chain. The benefit is mechanical: zero re-entry, zero input errors, real-time (or near-real-time) synchronisation across all critical flows.
4 symptoms that signal an urgent integration need
- Stock-outs on the website while the warehouse is full: ERP stock and storefront stock are not synchronised.
- Invoice lead time of more than 48 hours after an order: the finance team is waiting for a manual order list from the previous day.
- Duplicate customers across your CRM, storefront and ERP: three systems, three conflicting records.
- Returns processed manually, credit notes entered by hand: the RMA (Return Merchandise Authorisation) workflow does not exist inside the ERP.
If you recognise two of these four symptoms, an integration project will deliver a positive return on investment in the short term.
The 6 critical data flows to synchronise
ERP–e-commerce integration is not a single flow. It is an architecture of six distinct channels, each running in different directions and at different frequencies. Each one must be designed separately.
Flow 1: orders (creation, status updates, returns)
This is the primary flow. As soon as an order is placed on the storefront, it must be created in the ERP with all its attributes: customer (new or existing), order lines, quantities, applied prices, discounts, payment method, shipping address. The ERP order then triggers picking, the despatch note and the invoice.
Recommended frequency: real-time via webhook for volumes under 500 orders per day; batch every 15 to 30 minutes above that threshold.
Flow 2: available stock (from ERP to storefront)
Available stock in the ERP — after reserving open orders — must be reflected on the storefront to prevent overselling. This is the most frequency-sensitive flow: stock updated every four hours is insufficient if you are also selling on Amazon or through a physical point of sale in parallel.
Real-time vs batch? Real-time (via webhooks or API push) is technically feasible but more resource-intensive on the ERP side. For most SMEs with daily volumes below 500 units sold, synchronisation every 5 to 15 minutes strikes the right balance between responsiveness and system load.
Flow 3: product catalogue and pricing (managing the single source of truth)
Who is the source of truth for product data? The ERP, where references, barcodes and cost prices are managed — or the storefront, where marketing descriptions, images and SEO are optimised? In practice the answer is often hybrid: the ERP is the source for logistics and financial data; the storefront is the source for commercial data.
The integration must therefore handle two product data flows in partially opposite directions, with a clear merge logic to prevent unwanted overwrites.
Flow 4: customers and B2B accounts (deduplication and a single identity)
In B2C, customer management is relatively straightforward. In B2B, it becomes a project in its own right: a buyer may have multiple storefront accounts (by subsidiary, by user), yet be linked to a single ERP account carrying specific pricing conditions, credit limits and a consolidated order history.
The integration must resolve deduplication (a customer who registers twice on the storefront) and propagate B2B conditions from the ERP to the storefront: negotiated prices, discounts, credit ceilings.
Flow 5: invoicing and VAT (accounting automation and multi-country rules)
The storefront collects payment. The ERP invoices and books the revenue. Without integration, reconciling collected payments (Stripe, PayPal, bank transfer) against ERP invoices is a time-consuming manual operation.
In 2026, the EU VAT OSS (One Stop Shop) regime requires merchants selling across multiple member states to apply the destination country’s VAT rate. An ERP integrated with the storefront must receive the customer’s country and transaction type in order to calculate and book the correct VAT automatically — no human intervention required.
Flow 6: returns and credit notes (RMA workflow inside the ERP)
A return on the storefront generates an RMA request, a return goods authorisation, a stock receipt and a commercial credit note or refund. Without integration, each of these steps is manual and error-prone: forgotten credit notes, stock not reinstated, refunds with no accounting trail.
A complete integration routes return requests from the storefront into the ERP’s RMA workflow, which manages the physical receipt and issues the credit note automatically.
Integration architectures: 3 approaches compared
Native ERP connector
Some ERP vendors provide official modules or certified connectors for the most common e-commerce platforms. This is the simplest option to deploy and maintain:
- Odoo has an official Shopify app in the Shopify App Store, plus WooCommerce and PrestaShop modules. Order, stock and customer flows come pre-configured.
- Dolibarr offers community modules for WooCommerce (DoliWoo) and PrestaShop, available on the DoliStore — less turnkey, but no additional licence cost.
- Axelor provides e-commerce connectors within its ecosystem, primarily for WooCommerce.
Best for: SMEs already running one of these ERPs that want integration without custom development. The trade-off: native connectors cover standard flows but may lack flexibility for atypical workflows.
iPaaS / middleware (Make, Zapier, Boomi, n8n)
Integration-as-a-Service platforms let you connect applications with no code (or minimal code) via visual workflows. Make (formerly Integromat) and Zapier target SMEs with accessible pricing plans. Boomi and MuleSoft address mid-market and enterprise customers that need more complex flows and guaranteed support SLAs.
Advantages: rapid implementation, high flexibility, no backend developer needed. Limitations: a Make workflow can hit operational limits at high order volumes (several thousand per day), and complex business logic — variant management or multi-country VAT — often requires advanced configuration.
For SMEs processing 50 to 500 orders per day with relatively standard flows, iPaaS often delivers the best cost-to-speed ratio. For a deeper comparison of available architectures, see our iPaaS platforms comparison for ERP.
Custom development via REST API
Shopify, WooCommerce and PrestaShop all expose documented REST APIs. Custom development lets you build exactly the integration you need, with no compromises on business logic.
When it is justified: very high volumes (above 1,000 orders per day), highly specific business logic (subscriptions, complex B2B, multiple marketplaces), or an ERP whose native connector is absent or too limited.
When it is not justified: for standard flows with a mainstream ERP. The development and maintenance cost of a bespoke integration quickly exceeds that of a well-configured native connector or iPaaS solution.
Market connector overview for 2026
Shopify
| ERP | Integration solution | Type |
|---|---|---|
| Odoo | Official Shopify app (Odoo.com) | Native |
| SAP Business One | Beehexa, Commercient | Certified third-party |
| Dynamics 365 Business Central | Native Microsoft Shopify connector | Native |
| NetSuite | Celigo, Boomi | iPaaS / connector |
| Sage | Ebaza, third-party connectors | Third-party |
Dynamics 365 Business Central has shipped a native Shopify connector maintained by Microsoft since 2022, making it the most stable option for BC users looking to connect their Shopify storefront.
WooCommerce
WooCommerce, as an open-source WordPress plugin, benefits from a wide ecosystem of community connectors:
| ERP | Solution | Type |
|---|---|---|
| Odoo | Odoo WooCommerce Connector (OCA) | Open source |
| Dolibarr | DoliWoo | Community |
| Sage 50/100 | eBridge, Patchworks | Third-party |
| ERPNext / Frappe | Frappe WooCommerce | Community |
Community connector quality varies. Before committing to a solution, check the date of the last update and compatibility with your version of WooCommerce (8.x in 2026).
PrestaShop
| ERP | Solution | Type |
|---|---|---|
| Odoo | Odoo PrestaShop module (OCA) | Open source |
| Dolibarr | PrestaShop module (DoliStore) | Community |
| SAP Business One / Dynamics 365 | Via iPaaS (Boomi, Make) | Middleware |
PrestaShop has an official addon marketplace where several ERP connectors are listed. Always verify compatibility with your PrestaShop version (1.7.x or 8.x — both remain in use across many SMEs in 2026).
Shopware 6: the rising platform in Europe
Shopware 6 is growing strongly in Germany, Austria and the Netherlands, with increasing adoption across northern Europe. Its API-first architecture makes it particularly well-suited to complex ERP integrations. Odoo connectors for Shopware exist (via the OCA ecosystem), and several specialist integrators offer bridges to SAP Business One and Dynamics 365 Business Central.
The 7 classic pitfalls of ERP–e-commerce integration
1. Stock conflict between real-time updates and batch
Selling the same item on your storefront and at a physical point of sale with hourly synchronisation is a recipe for overselling. Solution: define a safety buffer, or opt for near-real-time synchronisation on high-volume channels.
2. Product variant mapping errors
A shoe in size 9 navy and size 10 navy is the same parent reference with two distinct SKUs. E-commerce platforms and ERPs handle variants (size, colour, packaging) in fundamentally different ways. A misconfigured mapping creates orders with references that simply do not exist inside the ERP.
3. Multi-country VAT not automated
Without OSS VAT configuration, your ERP invoices at the domestic rate even for a customer in another member state. Automating the VAT rate based on the destination country has been a legal requirement since July 2021, and is a technical prerequisite to validate before any go-live.
4. Returns not tracked in the ERP
The customer returns the item, the storefront marks the order “refunded” — but no credit note is created in the ERP and the stock is not reinstated. This scenario arises systematically when the returns flow is not included in the initial project scope.
5. Duplicate customers across CRM, storefront and ERP
Three systems, three customer records. Without a deduplication rule based on email (B2C) or VAT/company registration number (B2B), you create duplicates that distort sales analytics and complicate accounts receivable follow-up.
6. API keys exposed in third-party connectors
Some marketplace connectors store your Shopify or WooCommerce API keys in third-party environments. If that third party is compromised, the attacker gains access to your entire e-commerce dataset. Prefer connectors that support OAuth 2.0 authentication over static keys, and verify the credential storage policy.
7. No flow monitoring (silent failures)
A webhook failing silently, a batch job that stopped running three days ago: without active alerting, you only find out when a customer calls to ask where their order is. Every production integration must include a monitoring mechanism: error logs, email or Slack alerts, a real-time flow dashboard.
Budget and ROI for an ERP–storefront integration project
Cost ranges
Costs vary significantly depending on the approach:
- Native ERP connector (Odoo, Dynamics Business Central): from a few hundred pounds/euros per year for the module subscription to €3,000–€8,000 for initial configuration by an integrator, depending on flow complexity.
- iPaaS (Make, self-hosted n8n): €50–€500/month platform subscription, plus €2,000–€5,000 for configuration depending on the number of flows and rule complexity.
- Custom development: €15,000–€40,000 for a first tranche covering orders, stock and customers, plus €5,000–€10,000 per year for maintenance and enhancements.
These ranges are indicative. Each project is shaped by the number of flows to cover, the complexity of business rules (multi-country VAT, B2B, multi-currency) and the initial state of the product catalogue.
Simplified ROI calculation
The return on investment for an integration project can be calculated directly:
- Hours saved: orders per day × re-entry minutes × 22 working days × 12 months.
- Value of hours saved: hours × fully-loaded hourly cost of the operator.
- Error reduction: cost of disputes, manual credit notes and stock corrections currently observed.
- Payback period: project cost divided by annual savings.
For an SME processing 50 orders per day with 5 minutes of re-entry per order and a fully-loaded hourly cost of €30, annual savings approach €33,000 (before error reduction). A native connector configured for €6,000 pays for itself in under three months.
Checklist before launching your integration
Before engaging an integrator or configuring a connector, review these eight points:
- Unified product master: are your ERP SKUs and storefront references aligned?
- Variant management documented: are the mapping rules for sizes, colours and packaging formalised?
- VAT rules defined: in which countries do you sell, which OSS regime applies, which rates do you use?
- Safety stock policy: what buffer should be applied to prevent multi-channel overselling?
- Returns process documented: is the ERP’s RMA workflow operational before the integration goes live?
- Customer deduplication rules: on which identifier (email, VAT/company number) do you match records?
- Monitoring plan: who receives alerts when a flow errors, and within what SLA?
- End-to-end test plan: have you planned a staging environment to validate all flows before production go-live?
To go further on sales cycle automation, see our guide Order-to-Cash: Automating the B2B Customer Cycle and Reducing DSO, our iPaaS platforms comparison for ERP, and our open-source ERP comparison (Odoo, Dolibarr, Axelor, ERPNext).
