When you sign your organization up for a Google Cloud product like Google Workspace, you provide the domain name you want to use with your services. This becomes the primary domain associated with your account. This must either be a domain you already own, or you can purchase a domain during the sign-up process.
When choosing your primary domain name:
You can't use a name that's associated with another Google account
A domain name can be associated with only one Google account at a time. If a name is associated with another Google account, you'll have to remove the domain from that account before using it with a new account. For details, see Remove a domain or domain alias.
Use a name that best represents your organization
Your primary domain becomes the main brand for your Google services. By default, users you add to your account get a username at this domain—such as firstname.lastname@example.org. They'll use this name to sign in to their Google account and as their email address (if you're using Gmail). You can also build a Google Site with your own custom address www.your-company.com. For details, see Map a new URL to your site.
Note: your domain cannot have non-English characters like á, ñ, ü, and ø, or any character from a non-English alphabet.
Don't sign up with a temporary name
Even if you're just testing Google services for a few users, sign up using your organization's actual domain—even if you're currently using that domain on the Internet. You can test Google services with an active domain without disrupting your existing mailflow or web site. For details, see Run a 5-step Google Workspace trial.