Included users
Every person with access counts, including the owner and pending invitations. Pro includes up to 2. Team includes up to 6.
Adding another person
On Team, open Settings → Billing or Team and add a user. Each additional user is $10 per month, or $100 per year on annual billing. Pro cannot buy a third user; move to Team instead.
What an extra user does not add
An extra user does not increase the email or SMS allowance.