> ## 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.

# signup_started Event

> Track when a user begins the signup flow in your SaaS application.

Fires when a user begins the signup flow. Use this event to measure signup funnel drop-off and optimize conversion.

## JavaScript

```javascript theme={null}
window._upstack('track', 'signup_started', {
  planId: 'plan_pro_monthly',
  source: 'pricing_page'
});
```

## Properties

| Property | Type   | Required | Description                       |
| -------- | ------ | -------- | --------------------------------- |
| planId   | string | No       | Pre-selected plan (if applicable) |
| source   | string | No       | Where signup was initiated        |

## When to Fire

* When signup form is opened
* When registration page loads
* When "Start Free Trial" button is clicked