If you are referring to a landline that uses a physical phone, you will need as many lines as the number of employees you wish to connect through the phone. u003cbr /u003eu003cbr /u003eHowever, if you are referring to a VoIP phone system, u003cstrongu003eyou can have a common number and multiple extensionsu003c/strongu003e that let you connect to all your employees. So if you have a hundred employees, you can choose to have a hundred lines, or one line and hundred extensions.