I added a brand new client to QBO accountant. How do they get access to QBO? Are they automatically invited or do I need to send them an invite?

You are automatically assigned the Primary Admin. You can invite your clients as Company Admins and/or Users.

https:// quickbooks.intuit.com/learn-support/en-ca/manage-users/add-delete-or-change-user-access/01/262171

Hello there. It's great to learn that your business is growing. I'll be happy to share more info so you can achieve your QuickBooks goals with ease. QuickBooks provides the flexibility you need in order to add your client. I encourage you to check out this helpful article here that provides the steps for adding a client to your account. Feel free to ask to ask other questions. I'll be here.