Yes, teachers with individual accounts can be added to a school account.

At the very bottom of the People Tab in your Account Settings is a list of any teachers who have individual accounts.

Invite them into the school account by clicking the ‘invite to school account’ button next to their name. They will be sent an email to ‘accept’ before being added to the school account.

You will need to have spare memberships available in your account or will need to purchase a membership to be able to bring them into the account.