I have the Verizon app and it shows exactly how much data each line uses. You can also set up each phone to get text alerts when you reach 50%, 75%, and 90% of your monthly data plan.
Thanks, I had the app once and deleted it. I’ll look into it.
Yes, I get automatic notices from Verizon when I get close to my limit. I can adjust my plan for one month, and change the next.