How to use YAMM if you use multiple Google accounts?

If you are logged in with multiple accounts under the same browser session, you might experience an error when using YAMM or other Google Workspace add-ons.

Note: This issue is on Google’s side, and YAMM, unfortunately, cannot do anything about it. It has existed for years, and Google still doesn’t want to fix it. If it affects you, please don’t hesitate to reply in the thread.

If you want to use YAMM, you must be logged in with one single Google account in your web browser. You can use one of the following methods:

Method 1: Use YAMM in an incognito window

Procedure

Open your web browser.
Click the three dots at the top right and select New Incognito Window. A new You've gone Incognito window opens.

Result

You can now log in to your Gmail account and start using YAMM.

info For users of Firefox or Safari, open a New Private Window.

Method 2: Use YAMM with your default account on your web browser

The default account is whichever account you signed into when you first set up the device. An error message prompts only when you trigger YAMM from an account that is not the default one on the browser window:

For example, if the email address alice@yet-another-mail-merge.com is the default account in the browser window, you can run YAMM without facing any issues. The avatar on the top right must be similar to the Google account you are using.

warning If you trigger YAMM using one of your accounts that is not the default one on your web browser, you will receive an error message.

If you want to change the default account on your web browser, we recommend that you:

Log out from your multiple accounts.
Log in with the new default account. The first account you log in with on your web browser will be the default account.

If you use YAMM with multiple Google accounts, then we recommend that you use method 3 and create a Chrome profile for each one.

Method 3: Create multiple Chrome profiles for each Google account

If you have multiple Google accounts and want to use YAMM, you must create a different Chrome profile for each different Google account.

We recommend that you log out from your multiple accounts before starting the procedure.

Procedure

Select the avatar at the top right and click + Add.

info For mac users, it is also possible to create a Chrome profile from the Profiles menu.

A Customize your Chrome profile pop-up window appears.
Add a name to your profile and click Done.

info You can also modify the profile picture and pick a theme colour.

A new Welcome to Chrome window opens.
This new window is dissociated from your main Google account.
Select the icon at the top right of your new Chrome window and click Turn on sync...

A Sign in to Chrome window opens.
Enter your other Google email address and click Next.
Enter your password and click Next.

You are now logged in with your second Google account in a new Chrome profile.
(Optional) Repeat the steps above if you want to log in with more than two Google accounts.