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Fortnox coverage in the Accounting API. Read and write support differ by resource.
| Resource | Read | Write / notes |
|---|---|---|
| Onboarding | ✓ Supported | Client-managed or Zwapgrid-managed; system ID: fortnox |
| Sales invoices | ✓ List + individual | ✓ Create |
| Supplier invoices | ✓ List + individual | ✓ Create |
| Customers | ✓ List + individual | Read only |
| Suppliers | ✓ List only | Read only |
| Journals | ✓ List + individual | ✓ Create |
| Chart of accounts | ✓ Supported | Read only |
| Financial reports | Balance sheet · Income statement · Trial balances (v2) | Read only |
“Not supported / contact us” indicates an unavailable unified endpoint. Native API access depends on the separate Proxy.1 availability shown below.
| Method | Resource | Support |
|---|---|---|
GET | accountingaccounts | ✓ Supported |
GET | accountingperiods | ✓ Supported |
GET | balancesheet | ✓ Supported |
GET | companyinformation | ✓ Supported |
GET | customers | ✓ Supported |
GET | customers/{customerId} | ✓ Supported |
GET | financialdimensions | ✓ Supported |
GET | incomestatement | ✓ Supported |
GET | journals | ✓ Supported |
GET | journals/{journalId} | ✓ Supported |
POST | journals | ✓ Supported |
GET | journals/{journalId}/attachments/{attachmentId} | ✓ Supported |
POST | journals/{journalId}/attachments | ✓ Supported |
GET | proxy/{systemUrl} | ✓ Supported |
POST | proxy/{systemUrl} | ✓ Supported |
PUT | proxy/{systemUrl} | ✓ Supported |
PATCH | proxy/{systemUrl} | ✓ Supported |
DELETE | proxy/{systemUrl} | ✓ Supported |
GET | salesinvoices | ✓ Supported |
GET | salesinvoices/{salesInvoiceId} | ✓ Supported |
POST | salesinvoices | ✓ Supported |
GET | salesinvoices/{salesInvoiceId}/attachments | ✓ Supported |
GET | salesinvoices/{salesInvoiceId}/attachments/{attachmentId} | ✓ Supported |
GET | salesinvoices/{salesInvoiceId}/attachments/printable | ✓ Supported |
POST | salesinvoices/{salesInvoiceId}/attachments | ✓ Supported |
POST | salesinvoices/{salesInvoiceId}/notes | Not supported / contact us |
GET | salesinvoices/payments | ✓ Supported |
GET | salesinvoices/{salesInvoiceId}/payments | ✓ Supported |
POST | salesinvoices/{salesInvoiceId}/payments | ✓ Supported |
GET | supplierinvoices | ✓ Supported |
GET | supplierinvoices/{supplierInvoiceId} | ✓ Supported |
POST | supplierinvoices | ✓ Supported |
GET | supplierinvoices/{supplierInvoiceId}/attachments | Not supported / contact us |
GET | supplierinvoices/{supplierInvoiceId}/attachments/{attachmentId} | Not supported / contact us |
GET | supplierinvoices/{supplierInvoiceId}/attachments/printable | Not supported / contact us |
POST | supplierinvoices/{supplierInvoiceId}/attachments | ✓ Supported |
GET | supplierinvoices/payments | ✓ Supported |
GET | supplierinvoices/{supplierInvoiceId}/payments | ✓ Supported |
POST | supplierinvoices/{supplierInvoiceId}/payments | ✓ Supported |
GET | suppliers | ✓ Supported |
GET | suppliers/{supplierId} | Not supported / contact us |
GET | trialbalances (V2) | ✓ Supported |
| Platform capability | Availability |
|---|---|
| Zwapgrid-managed connection | ✓ Supported |
| Client-managed connection | ✓ Supported |
| Custom scope selection | ✓ Supported |
| Proxy.1 | ✓ Supported |
The Proxy API can reach native Fortnox endpoints, subject to the underlying API and permissions. Discuss your requirements →
Create sales and supplier invoices in Fortnox through the unified API.
Use trial balances, balance sheets and income statements as inputs for reporting and credit assessment.
With an API key and an authorised consent, retrieve sales invoices through the Accounting API.
curl 'https://apione.zwapgrid.com/accounting/api/v1/consents/{consentId}/salesinvoices?Count=100&CurrentPage=1' \
-H 'x-api-key: YOUR_API_KEY' \
-H 'x-correlation-id: YOUR_UNIQUE_GUID'Replace the placeholders. Use a unique correlation ID per request. Page through results with Count (1–100) and CurrentPage (starting at 1).
Explore the API documentation →
Supported sales-invoice status filters: Paid, Unpaid, Overdue, Cancelled, Unbooked, Draft. Check the endpoint documentation before adding other filters. Schedule reads to suit your product’s freshness needs.
Reuse the unified interface as you expand to more systems and markets. Coverage and local requirements vary, so validate each new workflow.
Banks, fintechs, and SaaS companies across the Nordics use Zwapgrid to automate integrations, access clean accounting data, and onboard SME customers faster.
