# Track UTMs on Sumo Forms

## UTM attribution overview

Sumo UTM Tracking Integration only records UTMs that land on the checkout URL at purchase time. UTM Grabber keeps them in cookies on your site. This page explains how to pass that data through before the customer pays.

### What to expect

Legacy Sumo popups still run on some sites. Hidden field pattern applies.

### Steps

1. Map UTM fields on Sumo list builder forms

### Append UTMs with utm-out

```
<a href="https://your-checkout-url.example/product" class="utm-out">Buy now</a>
```

UTM Grabber rewrites the link with cookie values. Details: [utm-out class guide](https://docs.utmgrabber.com/books/102-getting-started-for-handl-utm-grabber-v3/page/appending-utms-to-the-buttons-using-class-name-attributes-selectively).

For webhook-based attribution after purchase, see [Send Sumo UTMs via Webhook](https://docs.utmgrabber.com/books/sumo-integration/page/end-umo-s-via-ebhook).