The Unlimited plans are based on the same number of unique contacts in your account for that month. The number of contacts in your account will determine the price of your plan.
A contact can have 1 phone number and 1 email.
Additional phone numbers are considered another contact.
There are two places to view your member count:
2. If not on a monthly plan, click on the menu at the top-right -> Billing & Plan Details. This will show the number of Current Unique Contacts in your account and how many more members that be added to the current plan.