ERP Integration for Ecommerce: Business Central and Fortnox

An ERP integration for ecommerce is rarely what sells a platform migration – but it is almost always what decides whether daily operations work afterwards. The ERP owns the truth about items, stock levels, prices and customers. The ecommerce platform owns the customer relationship. When the connection between them falters, you notice it immediately: incorrect stock figures, orders that get stuck and a customer service team cleaning up by hand.

This guide covers what an integration with Business Central or Fortnox actually needs to handle, which data flows you should specify before the project starts and where the most common mistakes are made.

What an ERP integration for ecommerce needs to handle

Whichever ERP you run, the integration comes down to the same core flows. What differs between systems is how data is exposed, how often it can be fetched and how much logic lives in each system. A good requirements picture starts by listing the flows, not by choosing technology:

• Products and items – who creates the item, and which fields carry over to the store?
• Stock levels – per warehouse or in total, and how quickly must the balance propagate?
• Prices and discounts – list prices, customer-specific prices, contract prices and volume tiers.
• Orders – from store to ERP, with the right payment method, VAT and delivery terms.
• Customers – customer numbers, organisations, delivery addresses and credit terms.
• Order status and invoices – back from the ERP so the customer can follow their order.

In a B2B business, the price and customer flows are usually the hardest. Customer-specific prices can live as price lists, discount matrices or contract lines in the ERP – and the store must be able to show the right price to the right logged-in customer without it taking seconds per page load. The fact that the platform handles B2B and B2C in one core makes this part simpler, because the customer logic is already in place instead of being built as an add-on.

Business Central and Fortnox – different starting points

Microsoft Dynamics 365 Business Central

Business Central is common among mid-sized companies and wholesalers, often with partner customisations. That means two Business Central installations are rarely identical: field names, dimensions and business logic can differ. Expect the integration work to be largely about mapping your specific setup – which fields are the source for what, and which logic already runs in the ERP and should not be duplicated in the store.

Fortnox

Fortnox is built for smaller and growing companies and is more standardised. That makes the base integration faster to get in place, but it instead requires you to be honest about where the boundary sits: advanced B2B pricing logic or multi-warehouse handling may not belong in Fortnox at all, but in the ecommerce platform or a PIM. Decide where each data type has its master before you build.

HDL Commerce has ready-made connectors for Business Central and Fortnox – and for systems such as Specter, Pyramid and Jeeves. You can see which ones fit your setup on the integrations page.

Real time or batch? Decide per flow, not per system

A common mistake is to demand “everything in real time”. It sounds safe but makes the integration more expensive and more fragile than it needs to be. It is better to set requirements per flow:

• Orders to the ERP – near real time, since picking and credit checks are waiting for the order.
• Stock levels – event-driven or at short intervals; the key is to avoid overselling fast-moving items.
• Prices – scheduled runs are usually enough, but customer-specific prices may need to be looked up on login.
• Product data – batch is almost always right; product information rarely changes second by second.

Also ask what happens when something goes wrong. An integration without an error queue, logging and alerts is an integration that gets debugged after the fact via angry customer emails. Specify retries, duplicate protection and a place where someone on the team can see what got stuck and why.

Common pitfalls – and how to avoid them

1. Unclear data mastership. If both the ERP and the store can change the same field, sooner or later they will contradict each other. Decide on one master per field and stick to it.
2. VAT logic that is assumed rather than specified. B2B prices excluding VAT, B2C including, reverse charge and cross-border sales – write the rules down before the build.
3. Test data that does not resemble reality. Test with your real product range and your real customer price lists, not ten demo products.
4. No plan for history. Should old orders and invoices be visible in the customer account? That determines how much data has to be migrated.

For those who want to go deeper technically: HDL Commerce exposes REST & GraphQL APIs, so custom flows and special cases can be built alongside the standard connectors. Documentation and examples are available on the developer pages.

Do not forget the surrounding flows

The ERP connection rarely lives alone. Payments from Klarna, Swish or Adyen need to be reconciled against invoices in the ERP, and shipping bookings via nShift or PostNord need order numbers and delivery data from the same chain. Map the entire flow from the customer’s click to the booked transaction before you build – most operational problems arise in the seams between systems, not inside them.

How to start right

A good integration project does not start in code but with a mapping exercise: which systems, which flows, which master, which volumes. With that picture in place you can assess both timeline and cost with reasonable accuracy – and compare pricing between alternatives on equal terms. If you are switching from an existing platform, a free migration analysis is included, and the integration landscape is a central part of it.

Want to see what your ERP connection would look like?

Book a demo and we will walk through your ERP, your flows and which of our ready-made connectors cover the need – and where customisation might be required. Get started here, and we will reply within 4 hours (weekdays).