To assign a company to a client, click the building icon in the Company column of the client from the Clients page. Select the company you want to assign to the client to assign the client to that company.
You can also create a new company for a client by typing in the dropdown that appears. For more information on creating companies, please see this article.
To reassign a company to a client, click on the existing company in the Company column of the client from the Clients page. Select or create the company you wish to assign to change the company assignment for the client.