sign invoice API
Sign invoice API
Record that a customer acknowledged an invoice. This stores their name and the time. It is not a qualified electronic-signature certificate.
Base URL https://invoicetxt.com Auth Authorization: Bearer itxt_live_…
POST/v1/invoices/{id}/sign
What “signed” means here
POST /v1/invoices/{id}/sign stores an acknowledgement: the name and the time. It does not issue a certificate, collect a drawn signature, or meet every country’s qualified electronic-signature rules. Use it when you want a clear record that the customer accepted the amount and the work.
The customer can also type their name on the public invoice page. That uses the same record. A second name is rejected so the acknowledgement cannot be swapped later.
| Field | Type | Description | |
|---|---|---|---|
name | string | required | Signer name, 2 to 80 characters. HTML is removed. A second acknowledgement returns 409. |
curl https://invoicetxt.com/v1/invoices/INVOICE_ID/sign \
-H 'Authorization: Bearer itxt_live_your_key' \
-H 'Content-Type: application/json' \
-d '{"name":"Jamie Cole"}'Status and webhooks
A successful call sets the invoice status to signed, unless it was already paid. Paid stays paid. Your webhook endpoint receives invoice.signed when you subscribe to that event.
The name must be 2 to 80 characters. HTML is stripped. Empty names return 422. An invoice that already has an acknowledgement returns 409.