How is it possible that a Standard User can change the mobile no of the administrator so that the Standard User now does the bank feed updates and the administrator cant?

I know how disappointing it is when a specific user can update your account information without your permission, @nazbin786.

I can provide the details on how this started and avoid this account hurdle moving forward.

A standard user may have known your access credentials for a long time. If you're saving your username and password in a browser and logged in to the same computer or mobile device, this may be why the standard user can access your account. They can easily edit or view it in your browser, like the Manage passwords in Chrome browser. You may need an IT specialist to put computer or browser restrictions to avoid risk.

In addition, you may want to check your online banking phone number to update your phone number.

Once they can access your QuickBooks Online (QBO) account, they can easily change the phone number to receive emails from QuickBooks or bank feed emails. If you wish to change the mobile number to receive bank feed updates or important text messages from QBO, here's how:

1. Login to QuickBooks Online.
2. Select your QBO account and then click the Letter on the upper right.
3. Choose Manage your Intuit Account.
   
   
    
4. Go to Sign in & Security.
5. Select Phone and then hit Change.
   
   
   
   

For your reference, please take a look at this article for more details on how to update your account information: Change your email, user ID, or password for QuickBooks Online.

Wanted to run a QBO account audit? I suggest using the Audit log and reviewing each system update and user's activity.

Let me know if you have other concerns about managing your account information. I'll be giving you out more help here. Stay safe and well!