Invoice webhooks

Receive webhook notifications whenever invoices are finalized or canceled. Invoice webhooks can be used to trigger actions in your application whenever an invoice is changed, for example to keep an external invoicing or accounting system up to date.

Events

Event	Description
invoice.finalized	Occurs whenever a new invoice is finalized.
invoice.canceled	Occurs whenever an invoice is canceled.

info

When an invoice is canceled, a webhook for the original invoice is triggered with the invoice.canceled event and the payload includes canceled_at and cancellation_invoice_id. We do NOT send a separate webhook for the cancellation invoice itself.

Example Payload

We return JSON-formatted content with the following structure.

Name	Example content	Description
id	a19e6168-3863-42a4-9454-48a2737d4ece	UUID of the trigger resource
type	invoice	Resource type
event	invoice.finalized	Event that triggered the webhook, lowercase, dot-separated
url	https://app.freispace.com/invoicing/invoices/a19e6168-3863-42a4-9454-48a2737d4ece/view	URL to the updated resource
data	{}	The invoice's information

{
    "id": "a19e6168-3863-42a4-9454-48a2737d4ece",
    "type": "invoice",
    "event": "invoice.finalized",
    "url": "https://app.freispace.com/invoicing/invoices/a19e6168-3863-42a4-9454-48a2737d4ece/view",
    "data": {
        "id": "a19e6168-3863-42a4-9454-48a2737d4ece",
        "number": "IN-26-1003",
        "date": "2026-04-24",
        "due_date": "2026-05-24", // nullable
        "due_days": 30, // nullable
        "subject": "Invoice IN-26-1003",
        "service_period_from": null,
        "service_period_to": null,
        "order": {
            "id": "a19e6172-0225-40cc-b453-a14e685412a0",
            "number": "OR-1000"
        }, // nullable
        "cost_center": null,
        "issuer": {
            "id": "a19e5d30-a5e8-4e0a-863f-505ed95980cf",
            "name": "Post House"
        },
        "recipient": {
            "client_id": "a19d6036-bfe7-4976-878c-ebc9be05fd52",
            "client_address_id": "a19d6036-d2f3-47d3-85f9-278890d3e094",
            "client_contact_id": null,
            "address": "BBC One\n2nd Floor Egton Wing\nBBC Broadcasting House\nLONDON\nW1A 1AA"
        },
        "billing_email_addresses": [],
        "currency": "GBP",
        "total_sum_net": 32000, // in cents
        "total_sum_gross": 38400, // in cents
        "payment_due_at": "2026-05-24",
        "cancellation_invoice_id": null,
        "canceled_at": null // format: "2026-04-24T07:52:52+00:00" (UTC)
    }
}