How can i limit data usage on my childs lined?

I'm looking for this, too. I don't want to turn their data off entirely in this case; I just want to limit it. This one's watching movies, etc, and sharing their hotspot - which I don't mind overall. However, they're taking up a huge number of GB, after which the entire family is slowed. Everyone else in our family uses MB or just a couple of GB.

This one's doing this while away from home, and they need their phone for work/school stuff. We're three days into a billing cycle, and everyone's data is crawling because of this one family member!

I've been through all the account stuff. I can deactivate their line, say - totally counterproductive - but I can't seem to simply limit that one line's data to one or two GB/month or similar.

Is there a way to limit data during sleeping hours on any of my lines? ATT has this feature and it sounds like other carriers do as well. Has T-Mobile made any progress in this area?? All the posts I am finding are over a year old!

You can turn their data on or off in your my.t-mobile.com.om account.  Outside of that, there isn't anything else you can do outside of tKing away their device temporarily, like before bed, to make sure they aren't staying up all night on their phone.

i am looking for it ,too