Does the ML25055 need a phone line?

Yes. It is a landline phone, not a VoIP device, so it connects to a standard telephone line or an analog port on a router or modem.

Can I add extra handsets?

It ships with one handset. It is a single-handset model, so plan on one answering point unless you add a separate phone.

Yes. The built-in answering machine takes calls and stores messages, so you do not need a separate machine or a carrier voicemail plan.

It has caller ID, but the name and number display depends on your phone provider sending that data.

For one desk it works well. For several desks or conference calls, look at a multi-handset DECT system or a conference phone instead.

At motorola.com, for $99.99, as of our latest check.

2 stores we checked sell it, including Office Depot, motorola.com.

$99.99at motorola.comChecked 1 h ago

Compared across 2 stores. Prices are checked against each store and labelled with when.

It checks today's price at every store, compares the alternatives and answers in about a minute.