Pleased to see you here in the Community. I'm here to share information about the number of accountants that can be added to QuickBooks Online (QBO).
Currently, all versions of QBO can only add up to two accountant users. While there isn't an option to add more than two users, I encourage you to submit a feedback to our Product Development Team for review when determining features to be added in updates. This can be done directly through your account by clicking the Gear icon in the top right corner, then select feedback. Please know that I'm going to submit feedback on my side as well.