The company canonical name is used by the system to a cultural fit score for new applicants. If you change this it will affect how applicants are ranked against vacancies.
Canonical name will be added to your account when it's being created by the Elevate Support Team.
Please note the Account level Canonical Company is overwritten by the Project level Canonical Company which in turn is overwritten by the Vacancy level Canonical Company
This means that if you set a different canonical company on the a project, this will override the one you have on the account level
Furthermore, if you set yet a different one on a vacancy level, this will override the account and the project canonical company
You can do this by selecting the 'Edit Company Ranking' tab under the your vacancy details
Search for the company and click on the Save button