Originally Posted by draver

I was also able to confirm it is per billing cycle on my last two trips.

Another perk T-Mobile has provided over the years is free lines every once in a while. I have accumulated four, and each of them gets the 5Gb of HS data roaming. I mention this since T-Mobile currently has a FREE LINE PROMO running for certain plans. I am maxed out at 12 lines so I do not qualify. I recommend contacting T-Force via Twitter to check on your plan eligibility for this promotion. From what I read on Reddit, some users are charged the new, $35 "Assistance Fee", some are not. You can always ask they give you an on line credit to cover that charge.