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TARGET_SYSTEM: fortnox
= Supported by Maesn
= On demand - contact us
= Not supported by fortnox

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How to connect to fortnox

To allow your customers to link your application with their fortnox accounts, you need to set up a fortnox App and submit your application credentials to maesn.
1

Prerequisites

Before you begin, ensure you have the following:
  • A Fortnox account with developer permissions.
2

Create the Fortnox App

In this step we create the App that a user can install into their fortnox instance to authorize the integration with your application.
  • Open the Fortnox Developer Portal (accessible via the menu in the top-left corner).
    • If you don’t see this option, check your permissions.
  • Click “Create Integration”.
  • Enter a name for your application.
  • Click “Create Integration”, then select “Edit”.
  • Add your Redirect URL: https://api.maesn.dev/auth/callback/fortnox
  • Add the following scopes: Bokföring (Accounting), Faktura (Invoice), Inbox, Koppla filer (Connect files), Kund (Customer), Leverantör (Supplier), Leverantörsfaktura (Supplier Invoice).
  • Save your changes.
3

Save Your Client ID and Client Secret

Once the app is created, your Client ID and Client Secret will be automatically generated.
  • Make sure to securely store your Client ID and Client Secret.
4

Configure your integration in the maesn API

In the last step, we setup your API tenant with your App’s details:
  • Get in touch with your contact person at maesn to submit the client id and client secret.
If you are not sure who your technical contact is, do not hesitate to reach out to us.
Last modified on March 19, 2026