Add a Secondary Domain

If your business operates more than one brand — or you run a subsidiary that needs its own email addresses — you can add a secondary domain to your existing Google Workspace account instead of buying a whole new subscription.

A secondary domain gives you:

• Separate mailboxes under the new domain (e.g. info@brand-two.com).
• Shared admin control — one super-admin manages both domains.
• One bill — everything rolls into the same Mercurie invoice.

Secondary domain vs. domain alias. A secondary domain is a distinct domain with its own users and mailboxes. A domain alias just forwards mail to an existing mailbox (e.g. sales@brand-two.com → sales@brand-one.com). This guide covers secondary domains.

Before you start

• You need super-admin access to the Google Workspace account.
• The new domain must be one you own or control — Google will require domain verification.
• You can add up to 600 secondary domains per Workspace account.

Step 1 — Open Google Admin Console

Sign in to admin.google.com as a super-admin for your primary domain.

Step 2 — Navigate to Domains

1. Click the menu icon (≡) in the top-left corner.
2. Go to Account → Domains → Manage domains.

Step 3 — Add the domain

1. Click Add a domain.
2. Enter the new domain name (e.g. brand-two.com).
3. Choose Secondary domain.
4. Click Continue.

Step 4 — Verify domain ownership

Google needs to confirm you own the domain. You'll be shown a verification method (usually a TXT record to add to your DNS).

1. Copy the verification value Google gives you.
2. Open your DNS provider (Cloudflare, GoDaddy, Namecheap, etc.).
3. Add a TXT record at the root of the new domain with the Google verification string.
4. Return to Google Admin and click Verify.

DNS propagation can take a few minutes. If verification fails immediately, wait 5–10 minutes and try again.

Step 5 — Set up MX records

Once verification passes, Google prompts you to add MX records so mail can flow to Gmail for the new domain.

1. Copy the MX values from Google.
2. Add them to the new domain's DNS, removing any existing MX records from previous mail hosts.
3. Return to Google Admin and click Activate Gmail.

If the new domain already receives mail elsewhere, plan a cut-over window so messages don't bounce during the switch.

Step 6 — Add users

The secondary domain is now live. You can create users under it:

1. In Google Admin, go to Directory → Users.
2. Click Add new user.
3. Choose the secondary domain from the domain dropdown.
4. Fill in the name and assign licences as normal.

What happens on the Mercurie side

Nothing changes in Mercurie — the secondary domain lives inside the same Workspace subscription, so:

• Same subscription on your Mercurie dashboard.
• Same invoice — user licences across both domains are summed into one line item.
• Same payment method renews everything together.

If you need separate billing or a different Mercurie tenant for the second brand, buy a new subscription instead.

Common questions

Can I turn a secondary domain into a primary domain later? Yes, but it's a manual process: you must remove the secondary domain and re-add it as a primary on a new Workspace account. Google does not support "promoting" a secondary domain.

Can users on the secondary domain see users on the primary domain? Yes — they're in the same Workspace directory, so the global address list is shared. If you need strict isolation, use separate subscriptions instead.

Do secondary domain users cost extra? They consume licences from the same pool as your primary domain users. If you're on a flexible plan, each new user adds to the monthly total. If you're on an annual plan, adding users beyond your committed count may trigger true-up charges at renewal.

What if verification keeps failing? Double-check the TXT record is at the root (apex) of the domain, not a subdomain. Also confirm there are no conflicting TXT records from previous verifications. If you're stuck, open a support ticket and we'll walk you through it.

Need help?

The Support entry on the Mercurie dashboard sidebar opens a ticket with the ops team. We're happy to help with domain verification, MX record setup, or user provisioning.