Data usage

If you're talking about data numbers usage via your internet provider, that's not a Mac problem. That's not even a Mac concern. That's just the results of your online activities and how your ISP accumulates your data usage.

If you disagree with the data, take it up with your ISP. They're the ones accumulating the data and reporting it.

We have three iMacs and one MacBook Pro online 24/7. We have never come close to our ISP's data cap. Macs do check for updates as do many apps, but that is not data intensive.

Your ISP should be able to provide you with data that shows where your data usage comes from. Comcast does; it's rudimentary, but it's there to view. That may well be a part of our plan, but they should be able to backup their claims. Your ISP that is.

What tasks and apps are you doing your work with/on? Without knowing what you're doing, anything offered here will be just purely guesses.

Let this guide you in reposting: Writing an effective Apple Support Commun… - Apple Community

If you're talking about data numbers usage via your internet provider, that's not a Mac problem. That's not even a Mac concern. That's just the results of your online activities and how your ISP accumulates your data usage.

If you disagree with the data, take it up with your ISP. They're the ones accumulating the data and reporting it.

I may be wrong but I believe Netflix monitors your connection to their servers and will dynamically adjust the content quality (and streaming data size) to provide the best viewing experience.

The new iMac may be able to receive faster network bandwidth; you may have upgraded your ISP connection speed, or the network fabric between you and the Netflix servers has become more efficient — allowing Netflix to sense the ability to deliver dynamically higher resolution (larger) content, and thus your monthly data usage increases.

Is there someone in your home that may be streaming Internet content without your knowledge?

Sorry, dunno why the system posted twice with one being a partial.