i have a sero plan, well if u are an existing customer they will not allow u to port your number to the new sero plan you will recieve a new phone number. This is only intended for new customers not current ones, or accually current ones with their contract done
this is the website of information about sero
http://wiki.howardforums.com/index.php/SPRINT_SERO
go here when u want to get the sero plan and use the email at the bottom
http://www.sprint.com/sero
enter
savings@sprintemi.com as an email and there you will be allowed in and buy a new plan