Party Pay is not relevant to the new plans - they don't have it.
If you currently have the older Visible Unlimited plan available prior to the new plans, Party Pay still exists and you can join or switch parties up until October 18. Most are simply joining the larger parties at this time. After October 18, party pay ceases to exist a and you'll be locked into your party pay price as long a the Visible Unlimited plan remains supported. No date has been specified for when that plan will be retired - despite some rumors floating about. At that time you'd need to switch to a new plan. Expand See More at:
https://community.visible.com/t5/Your-Account/Party-Pay-Update/ta-p/16819
