Starting today, Google Home smart speakers will be able to make voice calls free of charge to contacts and millions of businesses in the United States and Canada. The added feature begins rolling out today and strikes a major distinction between Google and Amazon, two of the biggest names in the market for smart speakers with an AI assistant inside.

Amazon’s Alexa brought voice calls to Alexa-enabled devices back in May, but each participant in a call must have the Alexa app on their phone and own an Echo, Echo Dot, or Echo Show. Google Assistant is able to make calls to any mobile phone or landline that’s in your Google Contacts or local businesses.

So now Google Home can make hands-free calls if you say things like “OK Google, call mom” or “OK Google, call a nearby florist.” And since Google Home learned how to recognize up to six distinguishable voices, Google Assistant may place different calls when you say “Call mom” versus your roommate, based on your Google Contacts.

Plans to bring free calls to Google Home were first announced earlier this year at Google’s annual I/O developer conference in May.

Calls to other countries can also be made with Google Home but require the use of Google Voice or Project Fi, and they incur charges based on respective rates for international calls on each of the services.

Project Fi and Google Voice users can also display their cell phone number on calls by connecting their account in the Google Home app. All other calls placed with Google Home will come up as unknown or no caller ID, though in the future the Google Assistant team plans to allow all users to have their number listed when placing calls with Google Home.

Emergency 911 calls are not yet supported.