Google Analytics Cross Domain Tracking

Cross-Domain Tracking Setup

WaveRez Partner Guide · For Web Managers

Overview
What You Need
GA4 Admin Setup ✅ Recommended
Script Installation (if no GA4 access)
Finding Your GA4 Measurement ID
Need Help?

Overview

When a customer visits your website and clicks through to your WaveRez booking portal, Google Analytics treats this as two separate users by default. This means your marketing team can't accurately see which ads, search results, or campaigns are actually driving bookings.

Cross-domain tracking fixes this by linking your website and the booking portal together, so the full customer journey is measured as a single session — from first visit to completed booking.

💡 Why this matters for you
Without cross-domain tracking, bookings appear to come from "direct" traffic in your analytics, even if a customer originally arrived from a paid ad or Google search. This makes it impossible to know which marketing channels are actually working.

What You Need

Before getting started, make sure you have access to the following. Which method you use depends on what you have available.

What	Why You Need It
🔑 GA4 Admin Access	Required for the simplest setup method — no code changes needed
🏷️ GA4 Measurement ID	Your `G-XXXXXXXXXX` ID from Google Analytics. Required for script installation only. See Section 05 if unsure where to find this
🖥️ WordPress Admin Access	Only required if installing via code rather than through GA4 directly
🌐 Your Domain	Your website's domain name — e.g. `yoursite.com` — used in the configuration

⚠️ Not sure which method applies to you?
If you have access to your Google Analytics account, use the GA4 Admin method — it's the easiest option and requires no code changes. If you only have access to your website, use the script installation method.

GA4 Admin Setup

✅ Recommended — No code changes required

This is the simplest method. Everything is configured directly inside Google Analytics.

Step 1 — Open Google Analytics

Go to analytics.google.com and sign in to your account.

Step 2 — Go to Admin

Click the gear icon labelled Admin in the bottom-left corner of the screen.

Step 3 — Open Data Streams

Under the Property column, click Data Streams, then click on your website's data stream.

Step 4 — Click "Configure tag settings"

Scroll down to the section labelled Google Tag and click Configure tag settings.

Step 5 — Click "Configure your domains"

This is the cross-domain linking section. Click to open it.

Step 6 — Add both domains

Click Add condition and add the following two entries, both using Exactly matches as the match type:

Match Type	Domain to Enter
Exactly matches	`reservations.waverez.com`
Exactly matches	`yoursite.com` (replace with your actual domain)

Step 7 — Save

Click Save. The change takes effect immediately — no further steps needed.

✅ That's it!
Once saved, Google Analytics will automatically pass session data between your website and the WaveRez booking portal. No code changes or re-publishing required.

Script Installation

⚠️ Use this method only if you don't have GA4 admin access

If you don't have access to your Google Analytics account, you can set up cross-domain tracking by adding a small script to your WordPress website using a header injection plugin such as WPCode or Header Footer Code Manager.

You will need your GA4 Measurement ID for this. See Section 05 if you're unsure where to find it.

Step 1 — Check if Google Analytics is already on your site

Before adding anything, check whether a Google Analytics tag is already installed to avoid loading it twice, which causes duplicate data.

Visit your website, right-click anywhere on the page, and select View Page Source
Press Ctrl+F (or Cmd+F on Mac) and search for G-
If a code starting with G-XXXXXXXXXX appears — your GA tag is already installed. Note that ID and use Option B below
If nothing appears — proceed with Option A below

Option A — Google Analytics is not yet installed

In your WordPress header injection plugin, paste the following into the <head> section.

⚠️ Replace G-XXXXXXXXXX (in both places) with your actual Measurement ID, and replace yoursite.com with your website's domain before saving.

<!-- Google Analytics + Cross-Domain Tracking -->
<script async src="https://www.googletagmanager.com/gtag/js?id=G-XXXXXXXXXX"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}

  gtag('set', 'linker', {
    'domains': [
      'reservations.waverez.com',
      'yoursite.com'
    ]
  });

  gtag('js', new Date());
  gtag('config', 'G-XXXXXXXXXX');
</script>

Option B — Google Analytics is already installed

Do not add a second full tag — this will cause duplicate data in your analytics. Instead, find your existing GA tag in WPCode or your theme settings and add only the linker lines below, inserted above the existing gtag('config', ...) line.

⚠️ Replace yoursite.com and G-XXXXXXXXXX with your website's domain and your actual Measurement ID before saving.

// Add these lines ABOVE your existing gtag('config', ...) line
gtag('set', 'linker', {
  'domains': [
    'reservations.waverez.com',
    'yoursite.com'
  ]
});

// Your existing line — do not remove or duplicate this
gtag('config', 'G-XXXXXXXXXX');

Finding Your GA4 Measurement ID

Your GA4 Measurement ID starts with G- followed by a string of letters and numbers, for example G-A1B2C3D4E5. Here's how to find it.

Step 1 — Go to analytics.google.com and sign in

Step 2 — Click the gear icon (Admin) in the bottom-left corner

Step 3 — Under the Property column, click Data Streams, then click on your website stream

Step 4 — Your Measurement ID is displayed in the top-right of the stream details panel. It looks like G-A1B2C3D4E5. Copy this value.

💡 Shortcut
If Google Analytics is already installed on your site, you can also find your Measurement ID by viewing your page source (right-click → View Page Source) and searching for G-.

Need Help?

If you run into any issues during setup or aren't sure which method applies to your situation, reach out to the WaveRez support team and we'll be happy to assist.

If your GA4 tag is managed through Google Tag Manager, cross-domain can also be configured through your GTM container. Contact WaveRez support for assistance with this setup.

🕐 Hours	8AM – 5PM, 7 days a week
📧 Email	support@waverez.com
💬 Live Chat	Available via your WaveRez portal

Updated on: 23/02/2026

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