Connect Fortnox to Shopify — order, customer and invoice automatically
Do you sell on Shopify and keep your books in Fortnox? Then you probably spend time each week transferring orders, creating customers and reconciling payments by hand. An integration links the two systems so that a new order in Shopify automatically becomes a customer and invoice data in Fortnox. You change neither your store nor your accounting system — you get them to talk to each other.
Quick overview
In short: Connecting Fortnox to Shopify means that an order in the online store automatically creates a customer and invoice data in Fortnox, matches articles and stock, and reconciles payments from e.g. Klarna or Stripe — without manual entry.
How to get started:
- Decide which event should start the flow, e.g. "order paid in Shopify → customer + invoice data in Fortnox".
- Map the fields: article number, VAT rate, payment method and customer details should land correctly in Fortnox.
- Build the connection (e.g. in n8n, Make or Zapier), test it with a few real orders and reconcile against the accounts.
GDPR: orders contain personal data — map what flows, sign a data processing agreement and choose EU or self-hosting when you want the data to stay in Sweden.
What a Fortnox–Shopify integration solves
Without an integration, Shopify and Fortnox become two islands. Someone exports orders to a file, creates customers by hand and keys in invoice data after the fact. It takes time, mistakes creep in, and the reconciliation against payments lags behind. An integration removes the manual step: when something happens in Shopify, the right action takes place in Fortnox automatically.
Both Shopify and Fortnox have open APIs, and Shopify also sends webhooks — signals fired the moment an order is created, paid or refunded. That makes the connection rewarding to build: an event in the store triggers an action in accounting in real time, without anyone having to pull it manually.
What actually gets synced
A good way to plan the integration is to list which events in Shopify should trigger which actions in Fortnox. That makes it clear what should be automated and what can wait. Here are the most common flows for Swedish e-commerce:
| Event in Shopify | Action in Fortnox | Things to consider |
|---|---|---|
| New paid order | Customer created/matched + invoice data | Match on email/reg. number so no duplicates arise |
| New customer at checkout | Customer record in Fortnox with address and contact | Distinguish private and business customers (VAT, reg. number) |
| Article/product | Article number and price matched against Fortnox | Keep article numbers consistent in both systems |
| Payment (Klarna/Stripe) | Payment method and amount recorded | Fees from the payment provider booked separately |
| Return/refund | Credit note created in Fortnox | Link the credit note to the original invoice |
| Stock level | Updated on purchase and return | Decide which system is the "truth" for stock |
You don't need to build everything at once. Start with what steals the most time — usually order→customer→invoice data — and add articles, payments and returns as you go. You'll find more examples among our solutions.
Order, customer and invoice data step by step
The core of the integration is the chain order → customer → invoice data. When an order is paid in Shopify, you want the customer to exist in Fortnox (or be created if new) and a correct set of invoice data to be generated with the right articles, VAT and amount. That saves the manual entry and keeps the accounts in step with sales.
What determines whether the connection is stable is the field mapping — that every piece of information lands in the right place:
- Customer matching on email or the company registration number so existing customers aren't duplicated.
- Article numbers that match between Shopify and Fortnox, otherwise the line items fall wrong.
- The right VAT rate per article, including shipping and any fees.
- Payment method and order number included, so the reconciliation against payments runs smoothly.
Payments, fees and returns
Many Swedish stores take payment via Klarna or Stripe. Then it's not just the order total that has to add up — the payment provider takes a fee and often pays out in bulk, not per order. A well-considered integration records the payment method and amount on the invoice data and keeps the fees separate, so the reconciliation against the payouts comes out right.
Returns and refunds are the other half. When a customer gets money back in Shopify, a credit note should be created in Fortnox and linked to the original invoice. Handled manually, it's easy to miss, especially at high volume. Automated, you keep the accounts clean without extra work. If you want to see the full picture of what can be automated, read our guide on how to automate the business.
Ready-made app, your own connection, or help?
There are ready-made apps in Shopify's app store that connect to Fortnox, and they can go a long way for a simple store. But as soon as you have particular requirements — several payment methods, mixed private and business customers, specific VAT handling or return logic — a bespoke connection is often both more accurate and cheaper to run in the long term.
A good rule of thumb: try a ready-made app to get going, but build your own connection when the flow has to carry real work and the reconciliation must add up to the last öre. At Nuvid we build on top of the systems you already use — you change neither Shopify nor Fortnox, we get them to work together and keep the flow maintainable over time.
GDPR and keeping the data in Sweden
An order contains personal data: name, address, email and purchase history. When it flows between Shopify and Fortnox, GDPR applies. Shopify and several payment providers operate partly outside the EU, which places requirements on the legal basis for transfer. If you build the connection yourself, you can control where the intermediate layer runs — with self-hosting in the EU or Sweden, that part of the data stays here.
- Map which personal data flows from Shopify to Fortnox and where it goes.
- Sign a data processing agreement with the providers that process the data.
- Choose an integration platform that can run in the EU or be self-hosted when the data is sensitive.
- Transfer only the information Fortnox actually needs — less data, less risk.
Getting started — a small first flow
Start small and focused. Take the flow that steals the most time each week — almost always order→customer→invoice data — and get just that working reliably. Once it saves time and adds up in the accounts, you build on with articles, payments and returns.
- Write down how you currently transfer an order from Shopify to Fortnox, step by step.
- Decide which event should start the flow (e.g. order paid).
- Build the connection and test with a few real orders before going live.
- Reconcile against the accounts and add the next flow.
Want help setting it up right from the start? Get in touch and we'll look at your Shopify and Fortnox setup together. If you want to understand the whole ecosystem first, read our pillar guide on system integration for small businesses.
Want to see how this looks in practice? Explore our solutions, see case studies and platforms we've built, or get three free suggestions.