That is odd since the iPad sim works in an iPhone (data only but viop w/ Talkatone). Kind of like having a cellular iPod touch.I do not think that will work. For the same reason sticking an iPhone SIM with active Data in an iPad will not give you data on the iPad.!
I did for a short time (a couple of minutes) from an iPad rmini to an AT&T Unite and it worked. I don't know if you did it for a long time if it would flag your account, since the Hotspot accounts cost more.Can one use an iPad AT&T sim in MIFI device?
Sim size not accounted for would the MiFi need to be unlocked and GSM
or if an AT&T MiFi just stick it in?
Sierra Wireless AT&T Elevate Unlocked LTE 4G MiFi GSM Mobile Hotspot