How to create a sub-account with a different login name and password for my accountant with the highest level of permissions?

Currently, creating a sub-account with different login credentials is unavailable. However, QuickBooks Online (QBO) does provide user role management that allows you to customize or limit user access to specific tasks and data. I'm here to help you with this, JenGen.

You can invite your accountant to review your books, make corrections, and collaborate on any issues that include the management of accounts and sub-accounts. To do so, follow the steps provided below:
 

1. Sign in to QuickBooks Online as a primary admin.
2. Go to the Gear icon, then select Manage users.
3. Select the Accountants or Accounting firms tab.
4. Enter your accountant’s email address, then select Invite.
   
   

Once you send the invitation, your accountant will receive an email with a link to access your QuickBooks Online company, provided they have a QuickBooks Online Accountant.

For more information on managing user roles, I've added this article: User Roles and Access Rights.

After the accountant is added, you may also want to connect your online bank so transactions can automatically download and be able to categorize them. For guidance on this, please refer to this article:  Connect Bank and Credit Card Accounts to QuickBooks Online.

You can always post your reply below if you have any concerns when creating a sub-account or adding your accountant as a user. Please know we're always here to help you.