Hi dorretti,

It's good to hear you were able to change the user roles in your client's file. Your client will get an email invitation after you transferred the master admin role to them. Ask them to check their email and accept the invitation link to be the primary admin of their QuickBooks Online file. 

If you are trying to transfer the billing to your client?  When you remove a customer from your plan, they'll start paying for their subscription themselves. Their subscription won't be the same rate you paid since you got a ProAdvisor discount. 

Let's check the following steps below:
 

1. If you haven't already, make your client the primary admin of their company file.
2. In QuickBooks Online Accountant, go to Settings ⚙ and select Subscriptions and billing.
3. Select Accountant-billed subscriptions tab.
4. Select the client you want to remove.
Note: If the client is currently inactive, make them active first.
5. From the Action column▼dropdown, select Transfer billing to client.
6. Select Confirm transfer.

Once done, your client needs to log in and update their billing info to activate the QBO file.

Check this link to learn more about: Manage your ProAdvisor Preferred Pricing plan and ProAdvisor discount clients.

Drop by again in the Community if you have further concerns. I am around to help you.