Hello Belinde,

Thanks for your query!  :)

Currently, QuickBooks Online can only handle one company profile per subscription. If you have multiple companies, you'll have to sign up for once QuickBooks Online account per company. But the good thing is, you can use the same user ID for all your companies so that the accounts are listed in one place when you log in. 

Please check on the link below to know how to create multiple accounts using one User ID:

https://community.intuit.com/articles/1451852-how-to-create-multiple-companies-under-same-user-id-in...

Hope this helps! :)