Caller ID from the duplicate SIM


    Hi All,


    tmo_evan and all tmo supprot team members, I have a very basic question:


    Scenario: Multiple Device one number

    Status: Got the duplicate line setup and associated with the primary line. Now waiting for the duplicate SIM card to arrive

    Phones to be used: Samsung Galaxy S6 (SM-G920T) and iPhone 6S Model A1688


    Question: When I call from the primary SIM card, obviously my primary number will be shown. When I call from the duplicate SIM card, which number will be shown? Will it be my Primary line number (ideally this should be the case as per the scenario being evaluated) or the number that was assigned to that duplicate SIM card?  If someone calls my primary number, will both the device ring? I wanted to know this because I saw couple of threads where One Number Multiple devices had issues with the caller ID. Please suggest.

      All replies

      • azdreamscape

        Re: Caller ID from the duplicate SIM

        I'm not a T-Mobile rep, but I'll jump in with what I know...


        Both phones should ring, but there may be a slight delay between them (seconds).

        When you answer on one phone, the other will show a 'missed call'.

        Calls and texts out from either phone should show as coming from your main number.

        You should turn iMessage OFF on the iPhone.

        Text threads/discussions may not sync on both phones, but you WILL receive messages on both phones. All of the other party's replies will show up, but yours may only show on the phone they were sent from (maybe this has been fixed by now?).

        You don't need the DIGITS app on either phone for this scenario.


        All this is dependent on having your duplicate SIM/number properly 'attached' to your main number.

          • debjitjdv

            Re: Caller ID from the duplicate SIM

            Thanks azdreamscape. Your answer is very helpful and to the point. I have switched off the iMessage already. I am waiting for the duplicate SIM to arrive. Apparently, it was sitting in TMobile inventory for 3 days before being sent out to UPS Mail Innovation as the tracking ID shows. Originally I was expecting the SIM card this Friday but looks like it wont arrive before 13th or 14th. I shall update the thread once I receive the SIM card.

              • tmo_tim_b

                Re: Caller ID from the duplicate SIM

                Hello debjitjdv


                It looks like @azdreamscape pretty well covered what should happen. There have been issues along the way, though our teams have been working diligently to resolve them. We'll definitely want to know more about your experience once you get the SIM card. One thing I would like to add. While I understand you've already shut off iMessage on the phone, if you have any other iOS devices registered with the same Apple ID, you'll want to make sure your phone number is not listed on those other devices as a number that can be used for iMessage. You may want to go so far as to de-registering the number from iMessage altogether through Apple's site.


                Thank you for participating!