# Cross-Domain Settings

> Reference for each field in the Cross-Domain Settings of an AnyTrack property, with defaults, limits, and the verification steps.

The Cross-Domain Settings tell the Tracking Tag which links point to your other domains, and tell AnyTrack which conversions to copy back. This page explains each field. To learn when you need cross-domain tracking and how the data travels, read [Cross-Domain Tracking](/docs/cross-domain-tracking) first.

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**Configure the source property only**

All the Cross-Domain Settings live on the **source property**: the property where the visitor lands from your ad. The destination property needs its Tracking Tag and its integration, but no cross-domain settings.
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<Prerequisites
  title="Before you begin"
  items={[
    { label: "Your account is on the Personal, Advance, or Custom plan. Other plans show Upgrade to customize on these settings.", done: false },
    { label: "Each domain has its own property, with its Tracking Tag installed.", done: false },
    { label: "The destination property has the integration that records the conversion, for example Shopify.", done: false },
  ]}
/>

## Where to Find the Settings

1. Open the source property.
2. Open the **Settings** tab.
3. Scroll to the **Client-Side Tracking Settings** panel.
4. Find the **Cross-Domain Settings** section.

<Image align="center" alt="The Cross-Domain Settings section on the Settings tab of an AnyTrack property." border={true} caption="The Cross-Domain Settings section is on the Settings tab of the property." src={readmeAsset3} />

## Settings Reference

<Table variant="specs">

| Setting (dashboard label) | What it does | Default | Limits |
| --- | --- | --- | --- |
| **Additional Domains** | The domains of your other properties. The Tracking Tag tags each link that points to one of these domains. | Empty | 1 to 20 domains |
| **Enable to sync Conversions triggered on cross-domain properties with this property.** (Sync Conversions) | Links carry `atrefid`, and AnyTrack copies conversions from the destination back to this property. | Off | None |
| **Event Names** | The events that AnyTrack copies back. It shows only when Sync Conversions is on. | `Purchase`, `Lead`, `CompleteRegistration`, `InitiateCheckout`, `ViewContent`, `AddToCart` | Up to 20 events |
| **AutoTag UTM parameters for cross-domain properties.** | The Tag adds UTM parameters to the cross-domain links and replaces the UTM parameters that the links already have. | Off | None |

</Table>

### Additional Domains

Enter the root domain of each destination, for example `shop.com`. One entry covers the domain and all its subdomains, so `shop.com` also tags links to `www.shop.com` and `checkout.shop.com`.

- **Never add the domain of the source property.** If your advertorial is on `review.com`, do not add `review.com` or its subdomains. The Tag never tags links to its own domain.
- **Do not add affiliate offer domains.** Affiliate links get the Click ID through [AutoTag](/docs/autotag) and the affiliate network integration.
- **Do not add the domain of a cart platform from the [Integration Catalog](/docs/integration-catalog)** unless its setup guide tells you to. [ThriveCart](/docs/thrivecart), for example, does not need it.

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**Across AnyTrack accounts, add the exact host**

If the destination property belongs to another AnyTrack account, AnyTrack copies a conversion only when the host of the destination page is in this list. The host must match exactly: `shop.com` does not match `www.shop.com`. Add the root domain and each host of the destination pages, for example `shop.com` and `www.shop.com`.
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### Sync Conversions

The dashboard label is **Enable to sync Conversions triggered on cross-domain properties with this property.** This page calls it Sync Conversions.

- **On:** links to the destination carry `atrefid`. When the destination property records an event in the Event Names list, AnyTrack copies the event to the source property. The source property attributes the copy to the original session and sends it to its connected ad platforms.
- **Off:** links to the destination carry `atclid`. AnyTrack copies nothing back. Off fits one case only: one property that loads its own Tracking Tag on several root domains. The Tag on the other domain then keeps the same visitor.

AnyTrack recommends one property for each root domain. With two properties, turn Sync Conversions on. Without it, the conversion stays in the destination property, which has no ad click for it.

### Event Names

When you turn on Sync Conversions, the list starts with `Purchase`, `Lead`, `CompleteRegistration`, `InitiateCheckout`, `ViewContent`, and `AddToCart`.

- Remove the events that you do not want in the source property.
- Add `AddPaymentInfo`, `Upsell`, or a mapped custom event if you need it. The default list does not include them.
- The event name must match the name that the destination property records. If the destination maps an order to `Upsell`, add `Upsell`.

AnyTrack copies only the events in this list. If the list is empty, the links carry `atclid` and AnyTrack copies nothing.

### AutoTag UTM Parameters

When this option is on, the Tracking Tag writes these UTM parameters on each cross-domain link:

<Table variant="specs">

| Parameter | Value on the link | Example |
| --- | --- | --- |
| `utm_source` | The host of the source page | `review.com` |
| `utm_medium` | `referral` | `referral` |
| `utm_campaign` | The original source and medium, then the original campaign | `facebook / cpc - spring-sale` |
| `utm_content`, `utm_term` | The original values of the visit | `video-1` |

</Table>

Use this option when the owner of the destination wants to see which campaign sent each visitor, for example a partner in another AnyTrack account. The option does not change the attribution in the source property.

## Which Parameter the Links Carry

<Table variant="specs">

| Sync Conversions | Event Names | Parameter on cross-domain links | Conversion copied to the source property |
| --- | --- | --- | --- |
| On | At least one event | `atrefid` | Yes, for the events in the list |
| On | Empty | `atclid` | No |
| Off | Not shown | `atclid` | No |

</Table>

Both parameters carry the 34-character <Glossary>Click ID</Glossary> of the visitor on the source property. See [AnyTrack Identifiers](/docs/anytrack-identifiers).

<Callout icon="📘" theme="info">
**Seeing _atid on your URLs?**

The `_atid` parameter is not a cross-domain parameter. AnyTrack appends `_atid` on platforms such as Systeme.io, Shopify, and GoHighLevel so the platform collects the Click ID with its own data. Seeing `_atid` on page URLs or links is normal and unrelated to Cross-Domain Tracking. See [AnyTrack Identifiers](/docs/anytrack-identifiers).
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## Configure the Settings

<Video align="center" alt="Adding an additional domain in Cross-Domain Settings." border={true} caption="Adding an additional domain in Cross-Domain Settings." src={readmeAsset1} />

1. Open the Cross-Domain Settings of the source property.
2. In **Additional Domains**, enter the root domain of the destination. Press Enter after each domain.
3. If the destination is in another AnyTrack account, also enter each exact host of the destination pages.
4. Turn on Sync Conversions.
5. In **Event Names**, keep the events that you want in the source property.
6. Optional: turn on **AutoTag UTM parameters for cross-domain properties.**
7. Click **Save**.

## Verify the Settings

1. Open a page of the source property in a new incognito window.
2. Hover over a link that points to the destination. The link must show `?atrefid=`. If it shows `?atclid=`, verify that Sync Conversions is on and that the Event Names list is not empty.

<Image align="center" alt="A link to the destination domain tagged with atclid when Sync Conversions is off." border={true} caption="With Sync Conversions off, links to the destination carry atclid." src={readmeAsset4} />

<Image align="center" alt="A link to the destination domain tagged with atrefid when Sync Conversions is on." border={true} caption="With Sync Conversions on, links to the destination carry atrefid." src={readmeAsset5} />

3. Run [AutoScan](/docs/autoscan) on the source page. The Tracking Group of the cross-domain links is `anytrack` when Sync Conversions is on, and `crossdomain` when it is off.

<Image align="center" alt="AutoScan shows which links are affected by the cross-domain settings." border={true} caption="AutoScan shows the Tracking Group of each cross-domain link." src={readmeAsset6} />

4. Click the link and complete a test conversion on the destination.
5. Open the [Conversions Report](/docs/conversions-report) of the source property. The test conversion shows there with the original traffic source.
6. Open the Conversions Report of the destination property. The same conversion shows there as a referral from the source domain.

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**The Tag adds the parameter in the browser**

The Tracking Tag adds `atrefid` after the page loads. View Source does not show it. Inspect the link in the browser developer tools, or click it and read the destination URL.
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## Related Articles

- [Cross-Domain Tracking](/docs/cross-domain-tracking): when you need it and how the data travels
- [Advertorial and Shopify](/docs/cross-domain-advertorial-shopify): two properties in one account
- [Advertorial and Shop in Two Accounts](/docs/cross-domain-accounts-advertorial-shop): a partner shop in another account
- [Property Settings](/docs/property-settings)

<FaqAccordion
  title="Frequently Asked Questions"
  icon="fa-duotone fa-circle-question"
  items={[
    {
      question: "Do I need to add the subdomains of the destination domain?",
      answer: "No, not in one account. The root domain covers all its subdomains. If the destination is in another AnyTrack account, add each exact host of the destination pages too, for example www.shop.com, because AnyTrack compares the exact host before it copies a conversion."
    },
    {
      question: "Do I add the domain of the source property to the list?",
      answer: "No. Add only the destination domains. The Tracking Tag never tags links to its own domain, and an entry for the source domain does nothing."
    },
    {
      question: "Why do my cross-domain links show atclid and not atrefid?",
      answer: "Sync Conversions is off, or its Event Names list is empty. Turn on Sync Conversions, keep at least one event, and save. Open the source page in a new incognito window and check the link again."
    },
    {
      question: "Which events does AnyTrack copy back by default?",
      answer: "When you turn on Sync Conversions, the Event Names list starts with <code>Purchase</code>, <code>Lead</code>, <code>CompleteRegistration</code>, <code>InitiateCheckout</code>, <code>ViewContent</code>, and <code>AddToCart</code>. Edit the list to add or remove events. AnyTrack copies only the events in the list."
    },
    {
      question: "Can I change the UTM parameters that AnyTrack adds to cross-domain links?",
      answer: "No. The values are fixed: <code>utm_source</code> is the source host, <code>utm_medium</code> is <code>referral</code>, and <code>utm_campaign</code> holds the original source, medium, and campaign. You can only turn the option on or off."
    }
  ]}
/>