Depending on your current flexpay minute plan, you could always just upgrade to the Unlimited anytime minutes ($99) and then you can use the H@H because you have unlimited minutes. I am currently on 300min flexpay account, but with the add-ons I have, it would be $10 more a month to get unlimited minutes which is what I plan on doing, but even now I can make calls over UMA, it will just take from my 300min plan, but if it is unlimited, who cares right? Just my 2cents.