aid: fortnox
url: https://raw.githubusercontent.com/api-evangelist/fortnox/refs/heads/main/apis.yml
name: Fortnox
kind: company
description: Fortnox is a Swedish cloud accounting, ERP, and business-administration
  platform for small and medium-sized businesses and accounting bureaus. Its REST
  API at https://api.fortnox.se/3/ programmatically manages accounting and financial
  data - invoices, customers, articles, orders, offers, vouchers, accounts, suppliers,
  supplier invoices, projects, and financial years - authenticated with OAuth2
  Authorization Code Flow. Fortnox also publishes a duplex WebSocket event stream
  at wss://ws.fortnox.se/topics-v1 that pushes minimal change notifications across
  domains so integrations can react to changes instead of polling.
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
tags:
- Accounting
- ERP
- Invoicing
- Bookkeeping
- Sweden
- Nordics
- Finance
- Vouchers
- Customers
- SaaS
created: '2026-07-12'
modified: '2026-07-12'
specificationVersion: '0.19'
apis:
- aid: fortnox:fortnox-invoices-api
  name: Fortnox Invoices API
  tags:
  - Invoices
  - Billing
  - Accounts Receivable
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.fortnox.se/developer/resources-rest-api/invoices/invoices
  baseURL: https://api.fortnox.se/3
  properties:
  - url: https://www.fortnox.se/developer
    type: Documentation
  - url: https://www.fortnox.se/developer/resources-rest-api/invoices/invoices
    type: APIReference
  - url: openapi/fortnox-openapi.yml
    type: OpenAPI
  - url: collections/fortnox.postman_collection.json
    type: PostmanCollection
  - url: collections/fortnox.opencollection.json
    type: OpenCollection
  description: Create, read, update, cancel, and list customer invoices, plus actions
    such as bookkeep, credit, e-mail, and print. Represents accounts-receivable sales
    invoices in a Fortnox company file.
- aid: fortnox:fortnox-customers-api
  name: Fortnox Customers API
  tags:
  - Customers
  - CRM
  - Contacts
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.fortnox.se/developer/resources-rest-api/customers/customers
  baseURL: https://api.fortnox.se/3
  properties:
  - url: https://www.fortnox.se/developer/resources-rest-api/customers/customers
    type: APIReference
  - url: openapi/fortnox-openapi.yml
    type: OpenAPI
  - url: collections/fortnox.postman_collection.json
    type: PostmanCollection
  - url: collections/fortnox.opencollection.json
    type: OpenCollection
  description: Manage the customer register - create, retrieve, update, delete, and
    list customers with billing and delivery addresses, org/VAT numbers, terms, and
    default accounts used across invoices, orders, and offers.
- aid: fortnox:fortnox-articles-api
  name: Fortnox Articles API
  tags:
  - Articles
  - Products
  - Inventory
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.fortnox.se/developer/resources-rest-api/articles/articles
  baseURL: https://api.fortnox.se/3
  properties:
  - url: https://www.fortnox.se/developer/resources-rest-api/articles/articles
    type: APIReference
  - url: openapi/fortnox-openapi.yml
    type: OpenAPI
  - url: collections/fortnox.postman_collection.json
    type: PostmanCollection
  - url: collections/fortnox.opencollection.json
    type: OpenCollection
  description: Manage the article (product/service) register used as line items on
    invoices, orders, and offers - pricing, units, stock quantities, sales and purchase
    accounts, VAT, and EU/SE accounting settings.
- aid: fortnox:fortnox-orders-api
  name: Fortnox Orders API
  tags:
  - Orders
  - Sales Orders
  - Fulfillment
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.fortnox.se/developer/resources-rest-api/order/orders
  baseURL: https://api.fortnox.se/3
  properties:
  - url: https://www.fortnox.se/developer/resources-rest-api/order/orders
    type: APIReference
  - url: openapi/fortnox-openapi.yml
    type: OpenAPI
  - url: collections/fortnox.postman_collection.json
    type: PostmanCollection
  - url: collections/fortnox.opencollection.json
    type: OpenCollection
  description: Create, read, update, and list sales orders, and convert an order into
    an invoice. Orders carry customer, article line items, delivery details, and
    status through the sales workflow.
- aid: fortnox:fortnox-offers-api
  name: Fortnox Offers API
  tags:
  - Offers
  - Quotes
  - Sales
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.fortnox.se/developer/resources-rest-api/offer/offers
  baseURL: https://api.fortnox.se/3
  properties:
  - url: https://www.fortnox.se/developer/resources-rest-api/offer/offers
    type: APIReference
  - url: openapi/fortnox-openapi.yml
    type: OpenAPI
  - url: collections/fortnox.postman_collection.json
    type: PostmanCollection
  - url: collections/fortnox.opencollection.json
    type: OpenCollection
  description: Create, read, update, and list offers (quotations), and convert an
    accepted offer into an order or invoice. Offers hold customer, article lines,
    and validity for the pre-sales stage.
- aid: fortnox:fortnox-bookkeeping-api
  name: Fortnox Bookkeeping API
  tags:
  - Vouchers
  - Accounts
  - Ledger
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.fortnox.se/developer/resources-rest-api/vouchers/vouchers
  baseURL: https://api.fortnox.se/3
  properties:
  - url: https://www.fortnox.se/developer/resources-rest-api/vouchers/vouchers
    type: APIReference
  - url: openapi/fortnox-openapi.yml
    type: OpenAPI
  - url: collections/fortnox.postman_collection.json
    type: PostmanCollection
  - url: collections/fortnox.opencollection.json
    type: OpenCollection
  description: Post and read accounting vouchers (double-entry journal entries) into
    voucher series, and manage the chart of accounts and financial years that vouchers
    are booked against. Core general-ledger surface of the Fortnox API.
- aid: fortnox:fortnox-suppliers-api
  name: Fortnox Suppliers & Supplier Invoices API
  tags:
  - Suppliers
  - Supplier Invoices
  - Accounts Payable
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.fortnox.se/developer/resources-rest-api/supplier-invoices/supplier-invoices
  baseURL: https://api.fortnox.se/3
  properties:
  - url: https://www.fortnox.se/developer/resources-rest-api/suppliers/suppliers
    type: APIReference
  - url: openapi/fortnox-openapi.yml
    type: OpenAPI
  - url: collections/fortnox.postman_collection.json
    type: PostmanCollection
  - url: collections/fortnox.opencollection.json
    type: OpenCollection
  description: Manage the supplier register and inbound supplier invoices - create,
    read, update, and list suppliers, and register, bookkeep, and pay supplier
    invoices in the accounts-payable workflow.
- aid: fortnox:fortnox-projects-api
  name: Fortnox Projects API
  tags:
  - Projects
  - Cost Centers
  - Reporting
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.fortnox.se/developer/resources-rest-api/projects/projects
  baseURL: https://api.fortnox.se/3
  properties:
  - url: https://www.fortnox.se/developer/resources-rest-api/projects/projects
    type: APIReference
  - url: openapi/fortnox-openapi.yml
    type: OpenAPI
  - url: collections/fortnox.postman_collection.json
    type: PostmanCollection
  - url: collections/fortnox.opencollection.json
    type: OpenCollection
  description: Create, read, update, delete, and list projects used to tag invoices,
    vouchers, orders, and other records for project-based accounting and reporting.
- aid: fortnox:fortnox-topics-websocket-api
  name: Fortnox Topics WebSocket API
  tags:
  - WebSocket
  - Events
  - Change Notifications
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://www.fortnox.se/developer/guides-and-good-to-know/websockets
  baseURL: wss://ws.fortnox.se/topics-v1
  properties:
  - url: https://www.fortnox.se/developer/guides-and-good-to-know/websockets
    type: Documentation
  - url: asyncapi/fortnox-asyncapi.yml
    type: AsyncAPI
  description: Duplex WebSocket stream at wss://ws.fortnox.se/topics-v1 that pushes
    minimal change-notification events across domains (invoices, supplier-invoices,
    customers, articles, orders, offers, vouchers, projects, and more) so integrations
    react to changes instead of polling the REST API. Kafka-backed, at-least-once
    delivery, with per-topic offsets and up to 14-day replay.
common:
- type: AgenticAccess
  url: agentic-access/fortnox-agentic-access.yml
- type: DomainSecurity
  url: security/fortnox-domain-security.yml
- type: Authentication
  url: authentication/fortnox-authentication.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/fortnox-ab
- type: Website
  url: https://www.fortnox.se
- type: Documentation
  url: https://www.fortnox.se/developer
- type: Plans
  url: plans/fortnox-plans-pricing.yml
- type: RateLimits
  url: rate-limits/fortnox-rate-limits.yml
- type: FinOps
  url: finops/fortnox-finops.yml
- url: https://www.fortnox.se/developer/blog
  type: Blog
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com