
They offer high speeds on your phone up to a certain point then slow slow you down to 3g speeds.

They sell a $70 unlimited plan but cap your tethering after 5 gb. T-Mobile phone data and tethering isn't unlimited. Or, try PDANet+, which consists of a Google Play app and a Windows application that allow you to tether if your phone or provider don't otherwise support it. If nothing works, check with your cell phone maker - some phone makers have downloadable drivers for Windows that will make the USB tethering feature work. If you require activation, you'll probably be able to turn on USB tethering but your PC web browser will be directed to a page explaining that you have to pay to activate. It's bundled with my MetroPCS subscription, for example. Note that you may have to pay your cell phone provider to activate the USB Tethering feature. If that's not available, go into Settings, Network and see if there is a USB tethering option there that can be activated. If you see an entry marked "Charging only", tap it and make sure USB tethering is selected. You may need to go into notifications on your phone and make sure USB tethering is activated, as phones will often start in "Charge only" mode and have to be adjusted each time. Once plugged in, the computer should recognize the phone. You'll want to press "Wifi Direct Hotspot", by the way. It won't show on the play store on some carriers/phones so you may have to get it from ApkMirror. Works amazingly for tethering my iPad up on long car rides so I can watch some Netflix without buffering every 2 seconds. Each platform has a different method for getting it to tether to it correctly.

Just make sure you press the little help button in the app (after turning on the direct hotspot it pops up) and it includes instructions for different platforms (Android, iOS, Windows, etc). There is a way around it on Android by using an app called PdaNet+ but it's a little annoying to use. It was added in I think Android Lollipop. It has its own little channel it goes through. Even turning on a VPN won't get around it because tethering activity is set to not go through a VPN. Because both Google and Apple added a little flag to any tethering network activity that tells your carrier if you're tethering or not.
