STOP CHANGING SUBSCRIPTION SIGN UP DATES

STOP CHANGING SUBSCRIPTION SIGN UP DATES

When a comp;any signs up with us it cost the company 85.00 for 1 year, with one admin. each additional person they add cost 25,00 Because we are federal regulated We have to show the company sign up date, The problem is if one of them adds a new empliyee it changes the date to the date new emp;loyee added and it treats it like a new subscription. Its not a new subscription its just adding an authorized person. How can I make the crm not change the date?