---
title: "Changes to Mark a marketing event as cancelled"
method: POST
path: "/marketing/marketing-events/2026-09/events/{externalEventId}/cancel"
---

# Changes to Mark a marketing event as cancelled

`POST /marketing/marketing-events/2026-09/events/{externalEventId}/cancel`

> Every recorded change to this operation, newest first.

## Timeline

Changed in 2 of 8 revisions.

- **2026-10-16** (2026-09) `3afcf69ad1b4`: 1 info
- **2026-09-03** (2026-09) `e62ad9a49a20`: 6 warning, 2 info

## Changes

- **2026-10-16** (2026-09) `3afcf69ad1b4`: 1 info
  - added the required property `customProperties/items/maskedSubstrings/substrings/items/label` to the response with the `200` status
- **2026-09-03** (2026-09) `e62ad9a49a20`: 6 warning, 2 info
  - added the new `BREEZE_AGENT` enum value to the `customProperties/items/source` response property for the response status `200`
  - added the new `CONNECTED_ACCOUNT` enum value to the `customProperties/items/source` response property for the response status `200`
  - added the new `CUSTOMER_PORTAL` enum value to the `customProperties/items/source` response property for the response status `200`
  - added the new `DI_WRITE_TO_CRM` enum value to the `customProperties/items/source` response property for the response status `200`
  - added the new `MARKETS` enum value to the `customProperties/items/source` response property for the response status `200`
  - added the new `REVENUE_PLATFORM` enum value to the `customProperties/items/source` response property for the response status `200`
  - the endpoint scheme security `private_apps` was removed from the API
  - added the required property `customProperties/items/maskedSubstrings` to the response with the `200` status

---

[Operation](https://skmtc.dev/hubspot/apis/marketing-marketing-events/docs/marketing/marketing-events/2026-09/events/:externalEventId/cancel/post.md) - [API](https://skmtc.dev/hubspot/apis/marketing-marketing-events.md) - [Page](https://skmtc.dev/hubspot/apis/marketing-marketing-events/changes/marketing/marketing-events/2026-09/events/:externalEventId/cancel/post)