why companies have internal auditors eventhough they employe the services of external auditors?

Answer 1

nternal auditors are for internal controle and management purposes and external auditors audit the company accounts for the external stakeholders(e.g tax purposes, shareholders,and gov. authorities

Answer 2

It is to keep control of the Accounts. Nowadays companies don't resort to Financial Controllers rather they have VP Finance or CFO. So interal auditors fill the job of what Financial Controllers used to do in the outdated structure. Managerial Accountants have their own auditors for managerial control.