How do I transfer master administrator rights to a client before transferring the billing to them?

I can help you with the steps to transfer the master role, lhelman.

Here are the steps:

1. Click Gear, and then click Manage Users.

2. Select Add user.
3. Select Company Admin, then select Next.
4. Enter the new user's email address and their name. Click Save.
5. An email is sent to the person you invited to become a Company Administrator. They need to read the email, then use the activation link to set up their account. If they already have a QuickBooks Online user ID and password, they can use their existing credentials. If not, they can create a new user ID and password.
6. Once the new Company Administrator user has been invited and have set up their user ID and password, you must sign out and sign back in again as the Master Administrator in order to transfer the role to another user.

This article will also give you more information about transferring the master admin role: https://quickbooks.intuit.com/community/Account-management/How-to-transfer-the-role-of-Master-Admini....

Feel free to reach out to me if you have any questions. I'll be here to help.