Found it somewhere- My understanding is that it's a code employees can hand out to get a 20% monthly discount. It works for any T-Mobile one plan currently offered. It's for brand new customers making a brand new T-Mobile account. You must port in a number from any other carrier. The other carrier can not be metropcs or T-Mobile prepaid. It really needs to be another carrier. If you do this you get an account level lifetime 20% discount this is good for any numbers you add or anything you do on the account forever. So the rate with the promo for 2 lines is 2/80 all in taxes and fees included.