The plan works by creating an Amazon account for each family member, but there is no unified family account; as Amazon said, "the only thing that's shared is the payment." On the plan, one family member uses a "shared payment method" to pay for the subscription, which is a debit or credit card that Amazon uses to charge each month for the service. Each member can make purchases on Amazon and Amazon Music Unlimited with the shared payment method, and the subscriber of the plan will get notifications of all the activity going through the group.
Despite the group connectivity, each member will have "the same functionality as the Individual Plan subscription," with personalized music, library, playlists, and recommendations. The Individual Plan launched in October and marked Amazon's entry into the on-demand music streaming category, along with Apple Music and Spotify. Amazon's Family Plan directly sits alongside Apple Music's $14.99 per month Family Membership, which grants the full Apple Music experience for up to six people.
Read up on more information about Amazon Music Unlimited's new Family Plan here.