Apple Watch Error Code 406

I have the exact problem and have spent several hours on the phone with T-Mobile tech support and a Digits expert and still not resolved. Does ANYONE know what is going on? Has anyone resolved this. I don't want to keep calling T-Mobile when they don't know how to fix this. It is obviously a problem with the digits service. My watch was working previously and just doesn't anymore. PLEASE HELP.

Righty Oh, definitely something you'll wish to reach out to one of your Tech Experts to investigate and make sure you reference Chris' internal document when you call. 

A couple of questions for you- do you already have an Apple DIGITS line initiated on the account for the watch?  How many total lines do you have and are there any other mobile internet lines (such as for a mobile hotspot device or tablet?)  Do you have any other DIGITS lines, for example DIGITS Talk and Text?

I can't be too specific without peeking into your account (which we can't do in this forum unfortunately), but all of these are things that your Expert needs to investigate in order to fully understand why you're receiving this error message.

I currently have this same issue.  Apple Watch Series 5.  Called support 3 times now and been on phone for hours with no solution.  Watch has been hard set on TMO end and paired to my digits line.  Still get error code 406.  It is not paired to any other device and just got a new phone as well and has the same issue.  Someone needs to fix this.  An LTE watch is useless on TMO if it cannot be paired.

I'm having the same issue and have spent several hours on the phone with T-Mobile. They have been unable to solve the issue and are saying its Apple's issue. When calling Apple they say its T-Mobile's issue. Very disappointing service and still unable to activate my Apple Watch Series 7. Watch and phone have been reset multiple times with no resolution.

Experiencing this at the moment with my Apple Watch Series 4 44mm (stainless steel, cellular) (watchOS 8.1)  and iPhone 13 Pro Max (iOS 15.1) . It worked perfectly fine about five months ago but I cancelled the service for a few months and now that I want to add the service to it again it's giving me this issue. I've called T-Mobile for help and they had to manually set up the cellular option on their side but it still didn't reflect on my Apple Watch. Have already restarted the Watch, waited over an hour, unpaired and re-paired the apple watch, restarted iPhone and had them triple check the IMEI and EID on the account. 

I saw a post somewhere asking us to call T-Mobile and mention to follow DOC-437039 on their internal database…. waiting to get a call back shortly to try this..

-- Error Code: 406 Issue Solved --

I informed the T-Mobile Expert about the DOC-437039 (unsure if she found anything since this article is old) and she mentioned the iPhone line might’ve never to be reset to fix this issue. 

She "Unpaired and re-paired again the devices" from her side. I immediately received a text fro T-Mobile letting me know about my Apple Watch being paired to the iPhone. It is working now. 

I am having this problem on my Series 7 … and have spent close to 8 hours on the phone and in the stores to absolutely NO AVAIL!!!!!

nothing works, nobody knows what is going on… Rep is sending me a new phone to try…. (my phone works fine…. The problem is my watch!!!!)

before that could not make voice calls or receive them when out of range from my phone, or it was turned off…… THIS IS A NIGHTMARE!!!!!

I am currently have this issue spent 3 hrs at t-mobile while they was on the phone with tech support. An left with my watch still not connected to cellular. The watch it self says no sim An under plan no connection. We have deleted everything off my account and still says this same error code. Just bought series 8 watch yesterday at t-mobile.  I currently have 2 iPhones a iPad and a kids watch on my plan. 

PaulS wrote:

I have the same problem been on the phone for four hours. I'm very frustrated. Did you figure anything out yet?