---
title: "Flags an existing Draft invoice as Sent (\"Mark as Sent\"). This is a status change only - the invoice is not emailed to the customer."
method: POST
path: "/api/Invoice/MarkAsSent"
tags: ["Invoice"]
---

# Flags an existing Draft invoice as Sent ("Mark as Sent"). This is a status change only - the invoice is not emailed to the customer.

`POST /api/Invoice/MarkAsSent`

Only invoices currently in Draft status can be marked as Sent; any other status is rejected and nothing is changed. Zero-amount invoices are set to Paid rather than Sent. Use the SendWebhooks flag to fire the invoice_sent webhook event.

## Request body

- MarkInvoiceAsSentRequest — Request to flag an existing draft invoice as Sent, without emailing it to the customer.
  - `InvoiceID` integer, required — The ID of the invoice to mark as Sent. Must be a Draft invoice belonging to your account.
  - `DateSent` string, date-time — Optional Date Sent to record against the invoice (ISO 8601, e.g. 2026-08-17). Defaults to today in your user profile's timezone. Cannot be more than one day in the future.
  - `SendWebhooks` boolean — If true, fires the invoice_sent webhook event to any subscribed endpoints. Defaults to false to preserve existing integration behaviour.

## Response `200`

Returns the invoice number, resulting status and the Date Sent that was recorded.

- MarkInvoiceAsSentResponse — The outcome of marking an invoice as Sent.
  - `InvoiceID` integer — The invoice that was updated.
  - `InvoiceNumber` string — The full invoice number including prefix.
  - `TransactionStatusCode` string — The resulting invoice status. Normally "Sent", but zero-amount invoices are set to "Paid".
  - `DateSent` string, date-time — The Date Sent recorded against the invoice.
  - `Message` string — Human readable confirmation of what happened.

## Other responses

- `400` — Bad Request - missing InvoiceID, a DateSent in the future, or the invoice is not in Draft status.
- `401` — Unauthorized.
- `403` — Forbidden - caller lacks the roles required to manage invoices.
- `404` — Not Found - no such invoice in this account.

## Changes

- **2026-08-30** `e99843f3c878` — 1 info
  - endpoint added

[Change history](https://skmtc.dev/avaza/apis/avaza-api-documentation/changes/api/Invoice/MarkAsSent/post.md)

---

[API](https://skmtc.dev/avaza/apis/avaza-api-documentation.md) · [All operations](https://skmtc.dev/avaza/apis/avaza-api-documentation/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/avaza/avaza-api-documentation/revisions/e99843f3c878/schema)