Another non-Web use of an Internet connection is Voice over IP (VoIP, pronounced voip), which refers to the use of the Internet to create voice phone connections, often with a standard phone designed for a traditional landline.

Many Internet service providers today use VoIP for customers who purchase telephone service in conjunction with Internet service, and businesses have largely switched internal phone systems to VoIP systems instead of traditional switched systems.

VoIP tends to cost less to maintain in comparison with traditional phones, and it provides a high level of flexibility, including the ability to keep an existing phone number even if users move to a different office or a different state. However, VoIP requires a network connection to work, so if there is no network or Internet connection, the phones on a VoIP system will not function at all.