Register payment
Register a received payment, full or partial, against a customer invoice.
MCP tool fortnox_write → register_payment
write Confirm
Registers a payment on one customer invoice with the amount and the payment date you give, like Registrera inbetalning in Fortnox. A partial payment leaves the invoice open for the rest; a payment that covers the balance marks it as fully paid. Read the balance with get_invoice first. By default you confirm each call; you can switch that off for this tool.
Parameters
| Name | Type | Description |
|---|---|---|
| invoice_number string required | string | Invoice number from list_invoices or create_invoice. |
| amount number required | number | Amount received, in the invoice currency. |
| payment_date date | date | Date the money arrived. Default: today. |
tools/call
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "fortnox_write",
"arguments": {
"operation": "register_payment",
"arguments": {
"invoice_number": "2377",
"amount": 15000,
"payment_date": "2026-10-13"
}
}
}
}Example response
{
"content": [
{
"type": "text",
"text": "{ ... same JSON as structuredContent ... }"
}
],
"structuredContent": {
"invoice_number": "2377",
"paid_amount": 15000,
"payment_date": "2026-10-13",
"balance": 0,
"status": "fully paid",
"currency": "SEK"
},
"isError": false
}