Tethering plans are such robbery in broad daylight. I don't care what their excuse it. You paid for a certain amount of data, you should use it however you want.

I don't pay T-Mobile for tethering on my Nexus 4 on the $30 plan. It works fine.

How much do you tether? And to what sort of devices?

The problem I have with T-Mobile is their customer service reps are so poorly trained.

So depending on who I speak with, I am told I either need to pay the $15 for tethering or not. I pay it as I am a bit afraid to drop it never to have it return.

So can you tell me more about how you much you tether, and how often? Or if T-Mobile has ever given you anything official about your tethering being okay?

I too tether without paying (Nexus 4, to my laptop). I don't usually do it too heavily and until recently hadn't had any trouble from T-Mobile.

When I moved into my new apartment I used it more than usual (maybe 2-3 GB over a few days) and they started redirecting my traffic to a "Pay for Tethering" site. It's just user-agent based though so very easy to circumvent. Other than than I have had no issues.

Never anything official, and I do it rarely, so it doesn't really change my access pattern. I only tether when I'm in a coffee shop and the wifi there is bad. I'm not the sort of user that streams Netflix via tethering or something, although I know those people exist.

May I ask, how much do you pay each month after taxes and fees? (Assuming you opted for tethering.) Something like $45 + $10 taxes/fees?

T-Mobile prepaid plans are great in that regard. I only pay the New York sales tax on top of the quoted price (8.875% or something). My parents were on AT&T and they were paying close to $15 in mysterious fees + taxes per line, for dumbphone lines without data plans. I convinced them to move to T-Mobile prepaid, seems to work well so far.

Normal sales tax only. No other taxes/fees - they're all included in the basic rate. This is generally true of prepaid plans across all US carriers.