In Google Merchant Center, you are not restricted to only one website. If you are a merchant or an individual that owns several different websites, such as targeting different countries you can request a multi-client account.
Having a multi-account will allow you to add multiple domains using sub-accounts and have distinct merchant names for each added domain.
The only requirements are:
If you own one business with multiple countries’ TLD’s (top level domain ie: .com. .fr. .uk), then targeting each Google Shopping country requires you to register these TLD’s to a new account. Instead of creating multiple Google accounts with a new email address, you can use one account (multi-account) to register all the websites.
If you are a marketplace owner, you can then register an account for each of your marketplace resellers.
If your business has multiple brands.
Agencies can also benefit from a multi-account when managing client accounts
Step 1: Go to Wrench Icon > Account Settings
Step 2: Click on the tab Advanced Account Setup > Request Conversion
Note: This option is only available to account admins. If your account is already an advanced account, or is a sub-account in an advanced account, you won’t be able to request conversion.
Step 3: Choose your options. In most cases for retailers choose Merchant > International Retailers
Final Step: Google will send an email once this process is complete. Or check the status of your request by visiting the “Account settings” page.