An account manager is a person who works for a company and is responsible for the management of sales, and relationships with particular customers.The account manager does not manage the daily running of the account itself. They manage the relationship with the client of the account(s) they are assigned to.Generally, a client will remain with one account manager throughout the duration of hiring the company.Account managers serve as the interface between the customer service and the sales team in a company.he account manager does not manage the daily running of the account itself. They manage the relationship with the client of the account(s) they are assigned to.