> ## 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.

# Customer Properties

> Properties for identifying customers — email, phone, name, and address fields for identity resolution.

Customer properties are used for identity resolution and destination matching. Including these fields significantly improves match quality on advertising platforms.

## Properties

<CardGroup cols={2}>
  <Card title="email" icon="envelope" href="/pixel/events/properties/email">
    Primary cross-device identifier.
  </Card>

  <Card title="phone" icon="phone" href="/pixel/events/properties/phone">
    E.164 format phone number.
  </Card>

  <Card title="firstName / lastName" icon="user" href="/pixel/events/properties/name">
    Customer name fields.
  </Card>

  <Card title="Address Fields" icon="location-dot" href="/pixel/events/properties/address">
    Shipping and billing address.
  </Card>
</CardGroup>

## Quick Reference

| Property    | Type   | Required    | Description                             |
| ----------- | ------ | ----------- | --------------------------------------- |
| `email`     | string | Recommended | Customer's email address                |
| `phone`     | string | No          | Phone number (E.164 format recommended) |
| `firstName` | string | No          | Customer's first name                   |
| `lastName`  | string | No          | Customer's last name                    |

## Example

```javascript theme={null}
window._upstack('track', 'lead', {
  email: 'customer@example.com',
  phone: '+15551234567',
  firstName: 'Jane',
  lastName: 'Smith',
  value: 0,
  currency: 'USD'
});
```

<Tip>
  Events with email typically score EMQ 8-9 on Meta. Events with only IP address score 2-3.
</Tip>

## Privacy

All customer PII (email, phone, name) is normalized and SHA-256 hashed before being sent to advertising destinations. Raw values are never stored in destination platforms.