> ## Documentation Index
> Fetch the complete documentation index at: https://docs.upstackdata.com/llms.txt
> Use this file to discover all available pages before exploring further.

# addon_cancelled Event

> Track when a customer cancels an add-on feature or service.

Fires when a customer cancels an add-on feature or service. Use this event to understand add-on churn and feature value.

## JavaScript

```javascript theme={null}
window._upstack('track', 'addon_cancelled', {
  accountId: 'acct_abc123',
  subscriptionId: 'sub_def456',
  addonId: 'addon_advanced_analytics',
  addonName: 'Advanced Analytics',
  price: 4900,
  currency: 'USD',
  cancelReason: 'not_using'
});
```

## Properties

| Property       | Type   | Required | Description                  |
| -------------- | ------ | -------- | ---------------------------- |
| accountId      | string | Yes      | Account identifier           |
| addonId        | string | Yes      | Add-on identifier            |
| subscriptionId | string | No       | Subscription identifier      |
| addonName      | string | No       | Human-readable add-on name   |
| price          | number | No       | Lost add-on revenue in cents |
| currency       | string | No       | ISO 4217 currency code       |
| cancelReason   | string | No       | Reason for cancellation      |

## When to Fire

* When add-on is removed from subscription
* When add-on cancellation is requested
* When Stripe subscription item is removed