I recognize the urgency of being able to change the phone number of the QuickBooks Online (QBO), @Brea5.
I'll share information on how you can do it to stop receiving Intuit verifications.
For security reasons, only an admin can make changes to the Intuit Account. Our support team doesn't have access to update or modify your account information.
With this, only the admin of the QBO account can remove the phone number associated with the account. That said, I recommend reaching out to your boss so they can modify the phone number for you.
For a detailed process about recovering an account, check out this article: Recover your Intuit Account if you can’t sign in.
Here's also how you can update or change your email address, user ID, password, and other information for a QBO account: Update or change your Intuit Account sign-in information.
Let me know if you need further assistance with updating information on the QBO account. I'm always here to assist. Take care always.