This is a carrier in the USA (T-Mobile).
I did a quick search for the other 2 carriers using the term “[Carrier Name] Family Tracking” and Verizon and AT&T also seems to have it.
And according to https://www.t-mobile.com/support/plans-features/t-mobile-familywhere-app, it says:
FamilyWhere uses geolocation data from the T-Mobile network and is not affected by changes to device location settings.
So it appears that its using cell tower triangulation. Turning on Airplane Mode should stop it (assuming there isn’t a separate tracking app on your phone)
Oh Wow, What a wonderful tool for abusive spouses and abusive parents. And telecom companies are making money off of it. 🙃
TLDR: Its a good idea to get your own separate cellular plan.
Ugh, that one bugs me so much. The boundaries are that the wife doesn’t want to be tracked. By using this service at all, the husband is violating that boundary. That, and the “you have nothing to hide” mentality. Such a flawed mentality.
My wife and I use Life360 (yes I’m aware of what they do with data, currently trying to find an alternative), because I ride motorcycles and want my wife to know that I got to my destination safely, and she just likes sharing her location with me. Our kids have Pinwheel-managed smartphones, and even they know that I can see where they are at all times; it was a stipulation of them having smartphones in the first place.
It’s amazing what consent brings to the table.