How to Create a Google Tag Manager (GTM) Container – Client Reference Guide

How to Create a Google Tag Manager (GTM) Container – Client Reference Guide

Purpose

This article helps clients and their agencies: 
  1. Create a Google Tag Manager (GTM) container 
  2. Understand where GTM fits in their tracking setup 
  3. Avoid common mistakes during GTM setup 
Notes
Note: This article explains how to create a GTM container. 
Configuration of tags, triggers, and ad platforms is managed by the client or their agency.

What Is a GTM Container? 

A GTM container is a workspace in Google Tag Manager that holds: 
  1. Tracking tags (Google Ads, Meta, GA4, etc.) 
  2. Triggers (when a tag should fire) 
  3. Variables (data used by tags) 
Each website or application should ideally have one GTM container.

Prerequisites Before Creating a GTM Container

Ensure the following
  1. A Google account with access to Google Tag Manager 
  2. Website or landing page access (to paste GTM code) 
  3. Clear ownership between client vs agency 
Step-by-Step: Creating a GTM Container 

Step 1: Log in to Google Tag Manager
  1. Visit: https://tagmanager.google.com 
  2. Log in using your Google account 
Step 2: Create a New Account 
  1. Click Create Account 
  2. Enter: 
    1. Account Name (usually your organization name) 
    2. Country 
  3. Click Continue 
Step 3: Create a Container 
  1. Enter Container Name (recommended: website domain name)
  2. Choose Target Platform: 
    1. Web (most common) 
    2. AMP 
    3. Android 
    4. iOS 
  3. Click Create
Step 4: Accept GTM Terms 
  1. Accept Google Tag Manager Terms of Service 
  2. Your GTM container will now be created 

GTM Container ID (Important)

Once created, you will see a Container ID: 
GTM-XXXXXXX 
This ID is:
  1. Required if adding GTM inside platforms like Meritto Landing Pages
Installing the GTM Container Code After container creation, GTM provides two code snippets:

Code Snippet 1 (Head Section) 
Placed inside: 
<head>...</head> 

Code Snippet 2 (Body Section) 
Placed immediately after: 
<body> 

Notes
Important Notes: 
  1. Both snippets are mandatory 
  2. Installation is usually done by: 
    1. Website developer 
    2. Agency 
    3. CMS admin (WordPress, Webflow, etc.) 

Verifying GTM Installation 

Before using GTM: 
  1. Open GTM dashboard 
  2. Click Preview 
  3. Enter your website URL 
  4. Confirm GTM connects successfully 
If preview does not connect: 
  1. GTM code is missing or incorrect 
  2. Cache/CDN may need clearing 
  1. Use one GTM container per website 
  2. Avoid installing GTM multiple times 
  3. Always use Preview mode before publishing
  4. Maintain access control for GTM users 
  5. Document who owns: 
    1. GTM 
    2. Ad accounts 
    3. Analytics accounts

Common Mistakes to Avoid

  1. Creating multiple GTM containers for the same website
  2. Installing only one of the two GTM code snippets
  3. Publishing tags without testing 
  4. Giving full access to too many users 
  5. Assuming GTM automatically tracks leads (it does not)