How to add staff on specific client's file?

You can go to the Manage users window to add a staff or a user in your client's file, Justin.

Let me share these steps with you:

1. Go to the Gear or Settings ⚙ icon and select Manage users.
2. Click Add user, then enter the user’s required information.
3. Proceed to the drop-down list for Roles, then select the role you want to assign to the user.
4. Review the features this role gives access to.
5. Choose the Account management settings you want to manage if they are applicable for the chosen role.
6. Click Send invitation.

After that, the user will receive an email to confirm the invitation. They just need to follow the instructions given on how to create an Intuit account or access it if they already have one.

You can also check out this article for more details about this feature:

• Add, manage, or delete users in QuickBooks Online
• User roles and access rights in QuickBooks Online

Just in case you need additional resources about user management, I'll share these articles as well:

• Change your primary admin, payroll admin, or other payroll contact
• Sign in to multiple QuickBooks Online companies with one user ID

The Community is always here and ready to help if you need anything else when working in QBO.