Both Android and iPhone devices let you check data usage and which apps are the worst offenders so it's worth checking to see ...

Some apps use more background data than others because they are always syncing data, checking for updates and refreshing content ...

Background App Refresh consumes both battery power and data. When apps refresh in the background, they use your phone's resources, including the processor, network, and battery.

Disable background data for apps you rarely use by navigating to the app settings or your phone’s data usage menu. Turn off data sharing for personalized ads and diagnostics in Google settings.