I want to use a prepaid SIM card (text and calls only) anonymously. I bought the SIM card offline without providing any address or name.

I am now thinking about using a dumbphone I bought from Amazon and that I previously used my primary, "public" SIM card with (and would do so every once in a while). I only plan on switching the phone on when I want to make phone calls or write a text, probably once every one or two weeks.

Will this compromise my anonymity? If yes, to what degree and who would be able to get to know my identity? Would it be enough to buy a new dumb phone and only use the new prepaid SIM with it?

  • 2
    If you always carry your "personal" mobile phone with you as well, it shouldn't be too hard for a phone company to see that these two phones always connect to the same cell tower and switch towers at the same time. Thus linking these two phones to one user. In theory.
    – BadSkillz
    Apr 7, 2015 at 13:04

2 Answers 2


Your Amazon purchased hardware provides identity information unique to the phone and unrelated to the SIM card. You have linked the phone to yourself through that Amazon purchase and also via the previous use of that device with a SIM card with your identity.

The IMEI appears to be your main problem. Please see details of identifiers here - http://developer.samsung.com/technical-doc/view.do?v=T000000103

Simply stated your scheme does not provide anonymity.

  • Would both Amazon and my carrier know the IMEI? Is simply buying another phone that isn't linked to me enough?
    – fathom
    Apr 7, 2015 at 14:07
  • From whom are you trying to stay anonymous? If it an entity with the power to subpoena then I am sure they can (by design) correlate the details.
    – zedman9991
    Apr 7, 2015 at 14:42
  • Somebody with the power to subpoena and knowledge of my number.
    – fathom
    Apr 7, 2015 at 14:52
  • No. Someone with knowledge of your action in question and the power to subpoena. Simple to get to you from that point. Next step track or pick you up...
    – zedman9991
    Apr 7, 2015 at 15:14

Telecommunication providers have the ability to get your IMEI. If you used your normal SIM in a phone, then the new SIM in the same phone, they can link it to each other. This way, companies may compromise your anonymity.

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