You have an online store that sells and an ERP that runs the business. The problem: they speak different languages. Every day, someone on your team exports orders from WooCommerce to a spreadsheet, manually imports them into Sage, updates stock by hand and hopes there are no discrepancies. This double-entry cycle is not tolerable inefficiency: it is a source of errors, a barrier to growth and, at the volumes any ecommerce business handles in 2026, a real risk of overselling and accounting non-compliance. Integrating your online store with your ERP is no longer a luxury reserved for large enterprises; it is the lever that separates the SMEs that scale from those that drown in manual processes.
Why the ecommerce-ERP disconnect is the most expensive bottleneck for a digital SME
When the store and the ERP are not connected, every order follows a manual path: the operator copies it from the WooCommerce, Shopify or PrestaShop dashboard, enters it into Sage 200 or Business Central, updates the available stock on the selling platform and generates the invoice or delivery note. With 10 orders a day that process is annoying. With 100 orders a day it is unmanageable.
The real costs of disconnection fall into three categories:
- Direct operating cost: hours of staff time spent re-entering data that already exists in another system. Industry estimates for SMEs with 50–200 daily orders put this time at more than 3–5 hours per employee each week.
- Cost of errors: overselling due to out-of-date stock, duplicated invoices, accounting discrepancies that carry over to the year-end close.
- Opportunity cost: inability to scale campaigns because the operations team cannot keep up with the manual volume.
Integration solves all three at the root.
What it really means to «integrate» an online store with the ERP
Integration does not mean plugging in a generic connector and hoping everything works. A real ecommerce-ERP integration covers, at a minimum, five bidirectional flows:
- Catalogue synchronisation: the ERP is the single source of truth for products, prices and variants. The store consumes them; it does not duplicate them.
- Real-time stock control: every sale in the store deducts inventory in the ERP; every warehouse receipt updates the available stock on the website.
- Order management: orders confirmed in the store are automatically created as sales orders in the ERP, with their customer line, payment terms and shipping address.
- Invoicing and accounting: the invoice is generated from the ERP (not from the ecommerce platform) to guarantee accounting traceability and compliance with Verifactu and, where applicable, the Immediate Supply of Information (SII) required by the Spanish Tax Agency (AEAT).
- Returns management: return requests from the store generate the corresponding credit note in the ERP and return stock to the warehouse.
When the integration covers these five flows, the store and the ERP stop being two systems and become a single operation.
Comparison: integration options by ERP
There is no one-size-fits-all solution. The integration architecture depends on the ERP you already have, your order volume, the ecommerce platform and the available budget. The table below summarises the most common options for Spanish SMEs in 2026:
| ERP | Ecommerce platform | Integration mechanism | Suitable for | Points to watch |
|---|---|---|---|---|
| Odoo | Odoo eCommerce (native) | Native module, no middleware | SMEs that want a single system | Requires migrating the store to the Odoo module or using its frontend |
| Odoo | WooCommerce / PrestaShop | REST API connector (OCA modules or custom development) | SMEs with an established store who do not want to migrate it | Connector maintenance when Odoo is updated |
| Sage 200 | WooCommerce / Shopify | iPaaS middleware (Make, n8n, Celigo) or certified connector | Companies with Sage deployed and a WooCommerce store | Synchronisation latency; error handling in the middleware |
| Sage 200 | PrestaShop | Official Sage connector + PrestaShop module | Medium volumes (up to ~300 orders/day) | Connector licence cost; PrestaShop updates |
| Business Central | Shopify | Native Microsoft connector (included since BC 2022) | Companies in the Microsoft 365 ecosystem | Field-mapping configuration; multi-warehouse |
| Business Central | WooCommerce / Magento | Power Automate + BC API or third-party connector (KlubiQ, Anveo) | Organisations with an internal IT team or Microsoft partner | Connector licence costs; governance of Power Automate flows |
| Holded | WooCommerce / Shopify | Native REST API + Zapier / Make | Micro-SMEs and sole traders (low volume) | Public API with rate limitations; no advanced official support |
Integration with Odoo: the most complete option for growing SMEs
Odoo is, in 2026, the open-source ERP with the greatest adoption among Spanish SMEs that sell online. Its main advantage is that the eCommerce module is part of the same core as sales, purchasing, warehousing and accounting: there is no integration to build because everything shares the same database.
When an SME already has a WooCommerce store and does not want to migrate it, the most common architecture is a REST API connector that reads confirmed orders from WooCommerce via webhooks and creates them as sale orders in Odoo. Stock is updated in WooCommerce via an API call every time Odoo modifies inventory. This flow works well up to volumes of several hundred daily orders without requiring complex infrastructure.
If you are interested in going deeper on deploying Odoo as your central ERP, our ecommerce-ERP integration service details the complete process, from flow analysis to go-live with your real stock and customer data.
Integration with Sage 200: the middleware route
Sage 200 is the benchmark for many Spanish industrial and distribution SMEs. Its API is more closed than Odoo's, which means ecommerce integrations typically pass through a middleware layer: an automation platform such as n8n, Make (formerly Integromat) or channel-specific iPaaS solutions like Celigo.
The standard pattern: WooCommerce sends a webhook to the middleware when a confirmed order arrives; the middleware transforms it into Sage's format and sends it via API to Sage 200; Sage creates the sales order, deducts the stock and, when the warehouse prepares the shipment, updates the status in WooCommerce. The middleware also acts as an error buffer: if Sage is temporarily unavailable, the order is queued rather than lost.
A critical detail in 2026: the integration must ensure that invoices are generated from Sage (not from WooCommerce) to comply with the Verifactu obligations established in Royal Decree 1007/2023. WooCommerce order receipts have no fiscal validity; only the invoice issued from the approved billing system does.
Integration with Microsoft Business Central: the Microsoft 365 ecosystem
Business Central (formerly Dynamics NAV) is the natural choice for companies already embedded in the Microsoft ecosystem. Since version 2022 Wave 2, Microsoft includes a native Shopify connector that synchronises products, stock and orders without additional software. For WooCommerce or Magento, the cleanest route is to combine the Business Central API with Power Automate flows or certified third-party connectors.
The advantage of Business Central is its accounting depth: the ERP automatically generates journal entries when orders and invoices are confirmed, with complete traceability through to analytical accounting. The common challenge in ecommerce integrations is managing multi-warehouse and channel-specific pricing, which requires careful configuration in the connector mappings.
The five most common mistakes when integrating ecommerce and ERP
Drawing on experience accumulated in digitalisation projects across Castilla y León and the Canary Islands since 2007, these are the failures we have had to remediate most often:
- Synchronising stock in batches (every hour): in a competitive ecommerce environment, an hour's lag is enough to oversell. Synchronisation must be near-real-time (webhooks or polling every 1–5 minutes).
- Incorrect tax mapping: the VAT rate in the store must match the tax configuration in the ERP. An error here generates incorrect invoices and costly accounting corrections.
- Ignoring returns in the initial integration: the returns flow is usually more complex than the sales flow (stock reinstatement, credit note generation, customer refund). Leaving it for «phase two» consistently becomes the most expensive technical debt.
- Failing to manage customer duplicates: if the same customer buys with two different email addresses, the ERP creates two records. Without deduplication logic, the customer database becomes contaminated within weeks.
- Not testing with real production data before go-live: staging environments rarely replicate the real-world complexity of products with multiple variants, bundles or special pricing. Tests must be run with a sample of the actual catalogue.
Verifactu and electronic invoicing: the impact on ecommerce-ERP integration in 2026
Royal Decree 1007/2023, which regulates Verifactu, and Law 18/2022 (Crea y Crece), which establishes mandatory B2B electronic invoicing, change the landscape for any company selling online. The key points affecting the integration:
- Invoices must be issued from billing software that generates the chained hash required by Verifactu. WooCommerce invoicing plugins (such as WooCommerce PDF Invoices) are not approved billing systems.
- The integration must ensure that the store order triggers the invoice in the ERP, not the other way around. If the ERP does not receive the order, there is no valid invoice.
- For companies with more than 6 million euros in turnover, the SII (Immediate Supply of Information to the AEAT) obligations are already in force. The integration must ensure that issued invoice records are sent to the AEAT within four business days.
If you need to review how Verifactu affects you or what electronic invoicing means for your ecommerce, you can consult our ecommerce-ERP integration service, where we address tax compliance as part of the solution design.
Typical process for an ecommerce-ERP integration project
A well-executed integration project follows these phases:
- Current flow analysis: mapping all existing manual processes (where each piece of data is entered, who does it, how often). Without this analysis, the integration automates the chaos instead of eliminating it.
- Architecture design: selection of the integration mechanism (native, middleware, direct API), definition of the source of truth for each entity (product, customer, stock) and field mapping.
- Configuration and development: building the connectors, data transformations and error-handling logic.
- Testing with real data: validation of all flows (sale, return, stock synchronisation, invoicing) with a representative sample of the catalogue.
- Go-live and monitoring: production activation with intensive monitoring for the first 48–72 hours; configuration of alerts for synchronisation errors.
The typical timeline for a medium-complexity integration (one store, one ERP, catalogue of up to 5,000 SKUs) ranges from 4 to 10 weeks, depending on the quality of the initial data and the complexity of pricing and warehouse flows.
Frequently asked questions
Can I integrate WooCommerce with Sage 200 without changing my ERP?
Yes. You do not need to migrate to a different ERP to integrate your online store. The WooCommerce-Sage 200 integration is built on top of the Sage API and a middleware that translates orders from WooCommerce format to Sage format. What is required is that your version of Sage has the API enabled (Sage 200cloud includes it) and that field mapping (VAT rates, warehouses, invoice series) is correctly configured before go-live.
How long does it take for stock to synchronise between the store and the ERP?
It depends on the chosen architecture. With webhook-based integration (the recommended method), stock updates are nearly instantaneous: when Odoo or Business Central records a warehouse movement, the store reflects it in under a minute. With polling solutions (periodic queries), the typical latency is 5 to 15 minutes. Batch synchronisation over hours is never advisable for catalogues with limited stock.
Does ecommerce-ERP integration also work for marketplaces (Amazon, El Corte Inglés)?
Yes, with nuances. Marketplaces have their own APIs and order formats. The same middleware architecture that connects WooCommerce with the ERP can be extended to incorporate Amazon Seller Central, El Corte Inglés Digital or Leroy Merlin as additional channels. The key is that the ERP must always be the source of truth for stock: if you sell on three channels and stock is managed in three separate places, overselling is inevitable.
What happens if the ERP is down or there is a synchronisation error?
A well-designed integration includes error handling and retry queues. If the ERP is temporarily unavailable, the middleware stores the pending order and retries when the system comes back online. The responsible team receives an alert to review the orders in the queue. What must never happen is that an integration error results in a lost order or an ungenerated invoice without anyone being aware of it.