
The only additional piece of equipment that you need is an Analog Telephone Adapter (also referred to as an ATA) that allows you to connect your existing telephone to your home Internet. This equipment is typically provided on a free lease basis from the home VoIP provider that you choose, or you can use you own device if you prefer. You can also use IP phone(s) instead of using the ATA with your existing analog phones. The sound quality is better but there is more up front cost as IP phones are more expensive than the ATA devices.

First, there might be a very low cost or even free "basic" or "introductory" tier that's just so feature poor that the vast majority of customers will opt for the next level up, which will be the full-priced tier. Another common practice is a one- or two-year contract, each with a slightly lower price that are offered next to a significantly higher-priced month-to-month tier. Additionally, while most residential VoIP services offer unlimited calling, some vary their pricing on call restrictions. Those will come either in the form of minutes (with higher pricing attached to monthly overages) or geographic region. The latter usually start with nationwide calling and then tack on another charge for worldwide calling or even separate charges for different countries.

One advantage of the traditional landline services is that electrical power is sent over the telephone wires so your phone service is isolated from your house power. This meant that your phone service would continue to work if your house power went out. However, with VoIP, power is used not only for the ATA, or the IP phone, but it is also used for your Internet modem and router devices. No power also typically means no Internet service.