How to handle ecommerce when you migrate from Fortnox to Business Central

Short answer.

The answers usually point clearly at Abakion B2B Ecommerce, at Shopify, or at rebuilding the connection you already have, and knowing which one you're facing is worth more than another year renting a third-party app to bridge the two.

Fortnox is the closest system in this series to Business Central, because Lager and Offert & Order are first-party Fortnox modules with stock points, bins, batch traceability, reservations, FIFO valuation, real order documents and named price lists with quantity breaks. Almost all of that maps directly. What doesn't map is the connection: Fortnox's own Shopify and WooCommerce connectors move sales, refunds and payouts and explicitly not articles, stock or customers, so every link between your catalogue and your shop is a rented third-party app sitting on top of an integration licence of 189 kroner a month.

The three things that genuinely break are product variants, which Fortnox doesn't have at all, webhooks, which Fortnox doesn't publish for any business object so your integration polls at 300 requests a minute, and quantity-break prices, which survive into Business Central price lists and then can't be exported to Shopify because Microsoft's connector prices a temporary quote at quantity one.

Two routes fix that last problem: move B2C to Shopify with Microsoft's Shopify Connector, or move B2B into Business Central with Abakion B2B Ecommerce. Keeping the storefront and rebuilding only the connection is the third route.

What are the three options, and how do they compare?

There are three real options for ecommerce when you migrate from Fortnox to Business Central, and for a Fortnox company the first is a real contender, because your data model is close and your price lists map.

1. Keep the storefront and rebuild only the connection. The catch is that vendor support varies by supplier rather than by category, so check which of your current vendors actually connects to Business Central before assuming this route is available. And be clear about what changes commercially: today the integration is a subscription line, an integration licence plus a per-app fee, cancellable, metered and maintained by somebody else. In Business Central it becomes something you commission, own and regression test against a new major version twice a year. That's a real trade, in both directions.
2. Move B2C to Shopify and use Microsoft's Shopify Connector.
3. Move B2B into Business Central with the Abakion B2B Ecommerce app.

How much of an ERP does Fortnox already give you?

More than any other system in this series. Lager and Offert & Order are Fortnox's own modules, bought from Fortnox, not third-party apps.

Lager costs 369 kroner a month for the first user and 75 kroner per extra user. It tracks quantity in stock, reserved, available and inventory value per article. It distributes stocked items across different stock points at goods receipt, counts specific stock points or bins with automatic variance calculation, records batch numbers on receipt and traces a batch through to delivery, creates reservations from customer orders, values stock FIFO per location and posts stock movements to the accounts daily.

Offert & Order costs 99 kroner and creates real order documents: when a quote is accepted, you send an order confirmation.

The API matches. Fortnox has named price lists and a Prices resource whose records carry article number, price list, a from-quantity, a price, a percentage discount, an amount discount and a date. It has a separate warehouse API with stock points, stock locations, stock transfers, stock takings and production orders, where stock moves by creating and releasing documents rather than by writing a quantity field.

That's not an accounting package with bolt-ons. Most of it has a direct Business Central counterpart, and it works the same way.

You already own most of the ERP. What you've been renting is the connection.

What do Fortnox's own web shop connectors actually do?

They move money, not products. Fortnox Shopify books sales orders automatically, handles returns and refunds, and reconciles Shopify and Shopify Payments payouts. It does not move articles, it does not move inventory, and it does not move customers.

Fortnox WooCommerce does the same job for WooCommerce, posting daily sales vouchers to accounts receivable for reconciliation against payment provider payouts. Both require Fortnox Bokföring, and both are priced by monthly transaction count: nothing up to ten transactions, 295 kroner to a hundred, 495 to a thousand, 895 to five thousand and 1,095 kroner above that, where a transaction is every individual event linked to an order, such as a purchase or a refund.

And behind all of it sits the integration licence. Fortnox's own words: the integration licence costs 189 kroner a month and applies regardless of how many integrations you choose. So you pay your accounting vendor, monthly, for the right to have any integration at all, and then you pay per app on top, metered on order volume, billed through Fortnox as the merchant.

That's the shape of what you're migrating. Not a broken data model, a rented connection.

One premise before we go further. Business Central here means Business Central online. Microsoft states that you can't install Marketplace apps on-premises, including in Docker-based deployments, so on-premises isn't a realistic destination for anybody who needs connector apps, and we won't cover it.

Is anything forcing a move off Fortnox?

No. Fortnox is cloud SaaS, so there's no version to fall out of support, no end date and no letter with a date on it.

The one thing that did change is ownership. Fortnox left Nasdaq Stockholm with a last trading day of 24 July 2025, after a public cash offer from a consortium of EQT X and First Kraft, and it's now privately held. Whatever that means for the roadmap, it isn't a deadline.

Fortnox's own answer to a company outgrowing it is more apps rather than a bigger system, and it says so: this way you let your needs govern what your business system looks like, not the other way round. Around 500 integrations across more than 30 categories, with 209 in ecommerce alone.

So you have time. Use it on the decision rather than on the current setup.

Where do the stock and the orders actually live?

Often in a mid-tier, even with Lager in place, and which pattern you're in decides the size of the project.

Specter, for example, is a Swedish warehouse and point-of-sale platform, and its own description of the Fortnox integration is that financial business events are synced from Specter and posted in Fortnox. So Specter holds the stock and the orders and Fortnox receives the accounting. Ongoing WMS documents 300-plus companies using its Fortnox integrations.

Then check what happens to those vendors on the other side, because the answer is uneven and specific:

• Ongoing WMS builds and maintains its Fortnox integrations itself. For Business Central, its documentation says plainly that integrations between Ongoing WMS and Business Central are sold and maintained by third parties, and that Ongoing doesn't sell or maintain any integration to Business Central, naming seven integrators instead.
• Wetail, the Swedish WooCommerce house, sells a Fortnox plugin at 295 kroner a month and lists Fortnox and Spiris as its accounting systems. No Business Central.
• Wikinggruppen lists Fortnox, Specter, Visma.net and e-conomic among its business systems. Business Central isn't on the list.
• Askås is the counter-example, and the one to hope for: its integration list includes both Fortnox and Business Central as ERP options, so the shop platform can stay put and only the system behind it changes.

The lesson is dull but it saves money. Before anybody scopes this, find out which of your current subscriptions supports Business Central, which will need a different vendor, and which Business Central makes unnecessary.

What maps cleanly from Fortnox to Business Central?

Most of it, which is genuinely different from the rest of this series.

Order documents exist on both sides. Fortnox has orders and offers as real documents with cancel, email and print operations, and Business Central has quotes, orders and posted documents. So order history may actually be sitting in your accounting system, which means there's something real to migrate.

Price lists line up almost exactly. Fortnox has named price lists and a from-quantity on the price record with percentage and amount discounts. Business Central has price lists with an applies-to type and number covering customer, customer price group, customer discount group, all customers or campaign, with minimum quantity, unit of measure, currency and start and end dates on the line, and a documented rule that the best price is the lowest price with the highest line discount allowed on a given date. A from-quantity becomes a minimum quantity. That's a mapping, not a redesign.

Stock behaves the same way in both. Fortnox changes stock by creating and releasing documents, and so does Business Central. Stock points and bins become locations and bins. Batch numbers become lot numbers. FIFO stays FIFO.

Which is why the parts that don't map deserve more attention than usual, because in an otherwise smooth migration they're the ones nobody notices until go-live.

Does Fortnox have product variants?

No. There's no variant, option or variant matrix concept anywhere in the Fortnox API, so if you sell in sizes and colours those are separate Fortnox articles today and your shop is holding the variant model on its own.

Business Central models a range as one item with a `Code[20]` number plus Item Variant records with a `Code[10]` code, so somebody has to decide which of your articles were ever really separate products. That answer determines what your product URLs look like afterwards.

Does Fortnox have webhooks?

Not for any business object a web shop cares about. The only webhooks in Fortnox's published reference belong to its own company-formation order flow, with topics for order accepted, updated and deleted, signed with an HMAC SHA-256 digest. There are no webhooks for articles, stock, sales orders, invoices or customers.

So your integration polls, and it polls against a documented limit of 25 requests per five seconds per access token, which is 300 requests a minute.

Business Central online allows 600 API requests a minute in production, 6,000 per user in a rolling five-minute window, five concurrent requests, 100 connections per user, and 200 webhook subscriptions per environment.

Your Fortnox integration's ceiling is exactly a Business Central sandbox.

That isn't a criticism of Fortnox, it's a design constraint that has been shaping your integration for years, and it disappears. If you've been batching, caching and scheduling around 300 calls a minute, you can stop.

Do article numbers and customer numbers change when I move to Business Central?

Check your own data, because Fortnox doesn't publish its article and customer number lengths anywhere citable, and the Business Central side is fixed.

Business Central's item `No.` is a twenty-character `Code`, its customer `No.` is the same, Item Variant `Code` is ten characters and Location `Code` is ten characters. The `Code` data type converts to uppercase and strips leading and trailing spaces, so `abc-1` and `ABC-1 ` become the same item.

So before anybody plans a load, export your article register and count the long ones and the mixed-case ones. Ten characters for a location code is the one that catches Fortnox users, because Fortnox has two location levels, stock points and bins, and Business Central wants both inside ten uppercase characters.

Can Business Central publish volume prices to my web shop?

To a storefront reading Business Central live, yes. Through Microsoft's Shopify Connector, no.

Microsoft documents that when the connector calculates a price, it creates a temporary sales quote for the item with a quantity of one and uses standard price calculation, so only prices and discounts applicable at quantity one are used, and you can't export different prices or discounts based on quantity.

So a Fortnox B2B shop with volume breaks can move those breaks into Business Central price lists, where they fit perfectly, and then cannot push them to Shopify through Microsoft's connector. The data survives the migration and the shop can't see it.

That's a structural fact rather than a product flaw. A connector that publishes a catalogue has to publish one price per line. A storefront that reads the ERP live can ask for the price of this basket, for this customer, at this quantity.

Availability has a smaller version of the same shape. The Shopify Connector offers two standard stock calculations, projected available balance at today and free inventory not reserved, extensible with code. Fortnox's "disponibla" has to become one of those two, and that's a business decision rather than a mapping exercise.

Where does product content live after moving from Fortnox?

In your shop platform, exactly as it does now, and there's a trap in the Fortnox article record worth naming.

Fortnox articles have file connections and URL connections, so you can attach a PDF or an image to an article and associate a URL with it. That looks like a place to keep product content and it isn't one: it's an archive, without alt text, ordering or a merchandising model. There are no web or SEO fields in the API reference.

A Business Central item description is `Text[100]`, which is a product name rather than a page headline. What does change is that Business Central has item attributes, typed and inherited through item categories, which Microsoft's documentation names as search terms for customers in integrated web shops. That's somewhere structured to put the content the shop needs, which is more than you have now.

What happens to order history and customer logins?

Logins survive, because they live in your shop platform. Order history has something real to move and no tooling that moves it.

Order history is more interesting here than anywhere else in this series, precisely because Fortnox has real order documents. But Fortnox isn't on Microsoft's list of supported cloud migration sources, there's no Microsoft Fortnox migration extension, and the closest documented analogue, Microsoft's QuickBooks extensions, state outright that they don't migrate purchase orders or sales orders.

If Shopify is your storefront, the second half of the problem is documented too: Microsoft states that you can't import orders that are archived in Shopify, with the workaround being to unarchive them in the Shopify admin and to turn off automatic archiving so future orders are importable.

So decide deliberately, early, and in the same conversation as the go-live date. History stays queryable in Fortnox, or it arrives as opening balances, or it gets rebuilt from the shop. All three are legitimate.

Customer logins are the easy half. What breaks is the mapping, because a Fortnox customer number has to become a Business Central customer number and a Business Central number series will renumber it.

Is there a migration tool from Fortnox to Business Central?

No. Microsoft's cloud migration tool supports Business Central on-premises, Dynamics NAV, Dynamics GP 2015 and later, Dynamics SL 2015 and later, and any other SQL source using custom migrations, and the Generic Custom migration type added in 2026 release wave 1 is for SQL-based source systems. Fortnox is multi-tenant cloud SaaS reached through an HTTP API with no customer-accessible database, so that route doesn't apply.

Which sounds worse than it is. Your data comes out through an API you already know how to call, and it goes in through configuration packages or the Business Central API. Master data, opening balances and setup are ordinary work with a known shape. And you have an advantage most systems in this series don't: because Fortnox's model is close to Business Central's, the mapping conversations are short.

Does Business Central support SIE?

Yes, and it's a Microsoft feature rather than an ISV app.

Business Central's Swedish localisation lists SIE export and import as part of the Audit File Export app, available now, with four file types on the SIE tab of the audit file export document: year-end balances, periodic balances, object balances and transactions. You switch it on in Feature Management and map dimension codes to SIE dimension numbers on the Dimensions SIE page. Since version 22.1 the Swedish localisation is built on the W1 base app with this functionality in an extension installed by default.

One caveat to state rather than hide. SIE-Gruppen publishes a list of members who have declared their programs approved for SIE, and Fortnox is on it while Microsoft and Business Central are not. So Microsoft documents SIE import and export, and Microsoft hasn't made that declaration to the Swedish standards group. Both things are true, and a Swedish finance team will want to know both.

Does Business Central handle Swedish e-invoicing?

Through the generic framework or a partner access point, because Sweden isn't one of Business Central's named e-document localisations. This is the one genuine gap in the move and it belongs in the project plan on day one.

Sweden requires electronic invoicing to the public sector. Under the 2018 law, in force from 1 April 2019, invoices a supplier issues to a contracting authority must be electronic invoices conforming to the European standard, and authorities are obliged to receive and process them. SFTI, run jointly by the municipalities and regions, DIGG and Upphandlingsmyndigheten, references Peppol.

Business Central's E-Documents framework has named localised formats for Denmark, Germany, Norway, Australia and New Zealand and Spain. Sweden is not among them, so Swedish Peppol traffic goes through the generic framework or a partner access-point app rather than a Swedish localisation Microsoft maintains. It's a scoping item, not a blocker.

And one version to pin down. Microsoft states that support for Peppol BIS 2.0 and Peppol BIS 2.1 is removed in 2027 release wave 1, version 29.0, and replaced by Peppol BIS 3.0, because the Peppol network has phased out the older versions and most government and business platforms now mandate 3.0. Microsoft's required action is explicit: update all integrations, mappings and customisations to Peppol BIS 3.0.

Finally, a Fortnox habit that isn't a documented Business Central feature. Fortnox connects to all of Sweden's largest banks and to Skatteverket, and that plumbing is something Fortnox customers take for granted. It isn't named in Business Central's Swedish localisation feature list, so ask about it explicitly rather than assuming it comes in the box.

When does the Microsoft Shopify Connector fit?

When you sell to consumers, or to business customers whose pricing works at a single quantity tier, through one storefront rather than several marketplaces.

Architecture. The Shopify Connector is built by Microsoft, ships preinstalled with Business Central online, and runs on the job queue. There's no middleware to licence, no server, and nobody in the middle. It isn't available for on-premises deployments.

Data flow. Item sync is bidirectional and covers variants, images, barcodes, vendor item numbers, tags and metafields, and it exports item attributes, extended and marketing texts and translations. Inventory syncs across the locations you select, using projected available balance or free inventory. Customers and companies sync both ways, with mapping on email, phone or registration number.

Orders. Order import covers the Shopify online store, Shopify POS and Shopify B2B, and brings shipping costs, gift cards, tips, refunds, cancellations and payouts from Shopify Payments. Fulfilment tracking goes back to Shopify, and posted sales invoices are exported.

Tax. If you sell into the US, Shopify calculates sales tax at checkout and an engine such as Avalara sits behind Business Central for posting and filing.

Limits. Prices export at quantity one only, so volume breaks don't travel. A Shopify variant matrix combining two or more options can't be created by the connector, because Business Central has no option matrix and the connector uses the variant code as the only option. Archived Shopify orders can't be imported. Extension points are deliberately few, so Microsoft can follow Shopify's release pace without breaking changes. It's one shop per configuration, so other marketplaces need something else. And you have to stay current on Business Central versions.

Note the contrast with what you have now, because it cuts both ways. Fortnox's own Shopify connector moves less than Microsoft's does, since it handles sales, refunds and payouts and explicitly not articles, stock or customers. Microsoft's moves the catalogue and the stock as well. What it won't do is quantity pricing.

When does Abakion B2B Ecommerce fit?

When your customers have volume prices or their own agreed prices, and they reorder.

Architecture. Abakion B2B Ecommerce installs as an app in Business Central, the site runs on Azure, and the storefront reads live data from Business Central. There's no synchronisation job, no staging database, no integration to own, and nothing to regression test twice a year.

Data flow. Customer-specific catalogues, prices, agreements and currencies come straight from the ERP, and delivery dates come from Business Central's own availability calculation. Order history and reorder work from actual posted documents.

Product content. The accompanying Master Data Information app handles product content and variant matrices, which matters here because variants are the one thing Fortnox doesn't have at all, so this is where the size-and-colour question gets answered.

Tax. Avalara is supported for US sales tax.

Commercial shape. Fixed price on the initial project, then a subscription tiered by the number of active customers and the number of items in the shop.

The argument that lands hardest for a Fortnox customer. You have volume breaks in your price lists today. They map into Business Central price lists as minimum quantities, and then a catalogue-publishing connector can't carry them. A storefront reading Business Central directly asks for the price of this basket at this quantity, live. There's nothing to push out to the shop, because there's no out.

In what order should you sequence the two projects?

The accounts first, the shop once afterwards, and the subscription audit before either.

The most expensive mistake available to you is spending money on the Fortnox integration in the year before you leave Fortnox. Another app, another mapping, another workaround for the polling limit: all of it is written off on go-live day. Design any change to the current setup as thin and disposable and let the storefront land once, on the model you intend to keep. Two web projects in two years is the outcome nobody plans for and plenty of companies get.

The Fortnox specific advice is about the bill. List every line: the integration licence, each app and its transaction tier, the warehouse system, the shop platform's ERP connector, the shipping tool. Put next to each one what Business Central does natively and what it doesn't. That list is your business case and your project scope at the same time, and it's the one piece of preparation nobody regrets.

Nothing is switching off, so there's no rush. There's just the risk of paying twice for the same capability for two years, because nobody wanted to cancel a subscription.

When is neither Shopify nor Abakion B2B Ecommerce enough?

When your shop has to do something both routes deliberately trade away. Neither option fits if you:

• sell configurable products
• run punchout or EDI into your customers' procurement systems
• sell across several marketplaces
• operate a subscription model
• run a design-led consumer brand where the storefront is the marketing
• need volume break pricing published to a Shopify catalogue
• need a Shopify variant matrix with two or more options

For Swedish sellers the marketplace case is the common one, because your own shop plus a marketplace or two is normal and one shop per configuration doesn't cover it. If that's you, the honest outcome is that a mid-tier stays and Business Central becomes the financial and stock backbone underneath it. That's a smaller change than the other two routes and a perfectly good place to land.

But plenty of companies assume they're in that group without testing it, keep paying an integration licence and four app subscriptions, and never find out that the system they were integrating already did most of what the apps were for.

Where to start

Five questions, and you can answer all of them this week.

1. Do you have Lager and Offert & Order, and is your stock actually in Fortnox or in a warehouse system?
2. Add up the integration licence and every app subscription between your shop and your accounts. What does that number look like next to a Business Central licence?
3. Do your customers get volume prices, and does your shop show them?
4. How many articles have a number longer than twenty characters, and do any differ only by case?
5. Which of your current suppliers has a Business Central integration, and which doesn't?

The answers usually point clearly at Abakion B2B Ecommerce, at Shopify, or at rebuilding the connection you already have, and knowing which one you're facing is worth more than another year renting a third-party app to bridge the two.

Frequently asked questions

Both apps are on Microsoft Marketplace

• Shopify Connector, published by Microsoft
• Abakion B2B Ecommerce
• Abakion B2B Ecommerce product page

Sources

• Om Fortnox, Fortnox Group
• Offentligt uppköpserbjudande, Fortnox Group
• Fortnox prislista, Fortnox
• Fortnox Lager, lagerprogram, Fortnox
• Fortnox Offert & Order, Fortnox
• Fortnox paket, Fortnox
• Fortnox integrationer och integrationslicens, Fortnox
• Fortnox Shopify integration, Fortnox
• Fortnox WooCommerce integration, Fortnox
• Skräddarsy ditt affärssystem, Fortnox
• Fortnox API reference
• Fortnox API authentication, Fortnox Developer
• Specter integrationer, Specter
• Ongoing WMS Fortnox integrations, Ongoing
• Ongoing WMS Business Central integrations, Ongoing
• Wetail, Wetail
• Askås integrationer och partners, Askås
• Wikinggruppen partners och kopplingar, Wikinggruppen
• Lag (2018:1277) om elektroniska fakturor till följd av offentlig upphandling, Sveriges riksdag
• SFTI, Single Face To Industry
• SIE formatbeskrivning, SIE-Gruppen
• SIE-godkända program, SIE-Gruppen
• Kassaregister, Skatteverket
• Sweden local functionality, Business Central, Microsoft Learn
• Use SIE audit files export, Business Central, Microsoft Learn
• E-documents overview, Business Central, Microsoft Learn
• Deprecated features in the Business Central application, Microsoft Learn
• Deprecated features, Swedish version, Microsoft Learn
• Migrate on-premises data to Business Central online, Microsoft Learn
• Operational limits for Business Central online, Microsoft Learn
• Item table reference, Business Central, Microsoft Learn
• Item Variant table reference, Business Central, Microsoft Learn
• Location table reference, Business Central, Microsoft Learn
• Code data type, Business Central, Microsoft Learn
• Record sales price, discount and payment agreements, Microsoft Learn
• Work with item attributes, Microsoft Learn
• Synchronise items with Shopify, Microsoft Learn
• Synchronise orders with Shopify, Microsoft Learn
• Installing and uninstalling extensions in Business Central, Microsoft Learn