Hi there, balanced-accy.
In QuickBooks Online accountant's version, you can add as many clients as you want with their referral. However, you can't merge the accounts of your clients if they both have different subscriptions in QBO.
When they have different subscriptions, that means that their businesses have different legal entries and books. For this, the client will do the trick to merge their books if it has the same legal entries first then add you as their Accountant.
Count me in if you have questions in mind. I'll be a few clicks away. Take care.
