Connect with and learn from others in the QuickBooks Community.
Hello there, @patrice6.
I'd be glad to help you change the email address of your Accounting Firm.
The email address you're using to sign in can be changed in your Intuit Account. You can access it through your Accounting Firm in QuickBooks Online (QBO). I'd be glad to show you the steps.
Once done, you will receive an email for verification. Follow the onscreen instruction to finish the process. I've added this article for your additional reference: Change the email address you use to sign in.
You may consider visiting our QuickBooks Videos to learn more about the features available in this program that may help you with your future task: https://quickbooks.intuit.com/learn-support/.
Please don't hesitate to comment below if you need further assistance or questions. I'd be happy to lend a helping hand. Take care and have a wonderful day.