Starting in Android 4.3, Google added some code to AOSP that tagged your internet traffic when you were running a mobile hotspot, which made it incredibly easy for carriers to block tethering if you didn't have it included in your plan. But as of Android 6.0, this "tether_dun_required" tag has been removed, which means you no longer have to edit a database file to get tethering up and running.
Instead, all you need to do now is add a single line to your build.prop file, and tethering will be unlocked on Android 6.0 Marshmallow. Of course, your monthly data limits and standard overage charges will still apply, so you'll still need to keep an eye out on your data usage. Nonetheless, it's now incredibly easy to unlock Wi-Fi tethering for free on Sprint, T-Mobile, AT&T, or Verizon Wireless, and I'll show you how to do it below.
To get this one going, you'll just need either a root-enabled file browser or a dedicated build.prop editor app to add a single line to your build.prop file. If you don't already have one of these already, here are a pair of free options:
- Install FX File Explorer for free from the Google Play Store
- Install Build.prop Editor for free from the Google Play Store
I'll be demonstrating using a root file browser, but the basic premise should be just about the same regardless of which method you use.
The build.prop file is located in the system folder on the root partition of your device, so navigate to this directory with your root file browser to begin. From here, make sure the folder is mounted as "read/write," then long-press the build.prop file and choose "Open with," then "Text editor."
Next, scroll down to the bottom of your build.prop file and press the enter button on your keyboard to add a new line. From here, regardless of if you're using a file browser or a dedicated build.prop editor, the process will be the same. Simply add the following line, then make sure to save your changes before exiting:
Once you've added the line to your build.prop file, all that's left to do is to reboot your phone. When that's taken care of, head to the "More..." entry in Android's main Settings menu, then select "Tethering & portable hotspot." From here, simply turn on the "Portable Wi-Fi hotspot" option and connect your secondary device to begin tethering, and all the while, your carrier will be none the wiser.