Before you begin

To ensure that Google Tag Manager is configured to meet your business needs, consider the following points.

How many accounts are needed? Who should create them?

When you first set up a Tag Manager account, consider putting a strategy in place for who will manage the account over the long term, and how account ownership will be handled should a member of your team change roles.

It is usually best to set up one Tag Manager account per company. The company for which the tags will be managed should create the account in Google Tag Manager. For example, if an agency manages tags on behalf of an advertiser, the advertiser should create the Google Tag Manager account and then add the agency's Google account as a user. Read Setup and installation to learn how to set up an account.

Agencies can manage their clients' Google Tag Manager accounts by signing into their own Google Account (assuming that the clients have followed the best practice of (1) creating the Google Tag Manager account themselves and (2) adding the agency's Google account as a user). Also, multiple users can manage the same Google Tag Manager account, and each user can be given different access permissions by the account administrators. Read Users and permissions to learn more.

Are you a mobile app developer?

Set up one container per mobile app. Each new major version of your app should have a new container. (Minor updates to an app can use the same container since the config keys will likely be the same or very similar.)

To learn more about using Google Tag Manager for mobile apps, please visit our Developer Center.

Do you manage multiple web domains?

Typically, you set up one container per web domain. However, if the user experience and tags on a website span more than one domain, it's best to set up a single container that serves all the domains involved. Here are a few considerations:

• Configuration (rules, triggers, and variables) can't easily be shared across containers without using container exporting and importing, or by using the API. If the tags and firing logic is similar across domains, it makes sense to use a single container, because maintaining multiple similar configurations is time-consuming and error-prone.
• When someone publishes a container, all changes go live, regardless of domain. If you need to apply changes to one domain without affecting other domains, use a different container for each domain.

Read Setup and installation to learn about accounts and containers.

What tags do you have deployed on your website? Where?

Begin by identifying all of the tags you have deployed on your site and where they are deployed (e.g. in global headers or footers, on landing pages, confirmation pages, in response to button clicks, etc.)

Think about what information you want to collect and determine if there are additional tags you want to deploy. If the data you want to collect is not visible on the page, refer to the developer documentation for information on how to pass additional data to tags.

If all of your tags fire as pages are loading, and these pages can be identified by their URLs, a basic container implementation may be sufficient for your needs. Once your Google Tag Manager account and container have been created, simply place the provided container snippet (generated when you create the container) on every page of your website immediately after the opening HTML body tag. Read Setup and installation to learn about containers and the container snippet.

If your tag firing scenarios are more complex, you may want to implement a more customized container implementation. These custom solutions often implement a data layer, which is code that helps Google Tag Manager pass data from your site or app to your tags. You can learn about why and how you would use a data layer in our solutions guide, and how to set up a data layer on our developer site.