I have recently purchased two TREZOR devices with intent of setting one of them  up as a backup. After reviewing the setup tutorial there are two main differences from the setup process used in setting up the first device.

 1)  Rather than Setting Up a new TREZOR we are going to initiate the “Recovery” Process in setting up the second device

 2) Use the same 12, 18, or 24 word recovery key that was used to configure the first TREZOR and follow the recovery process instructions

 To begin configuring the second TREZOR, go to the Satoshi Labs website and click TREZOR Setup:

http://doc.satoshilabs.com/trezor-user/settingup.html#trezor-setup

  

    That in itself seemed to be a straightforward process, although I also wanted to know if there were any subtle nuances to be aware of where keeping two devices at the "same level" might create a problem. For example; in the case where the backup is at the original state and after some time, maybe years later, where updates done on the other “original” device may cause the backup to lose account access.  I also was wondering if there were any issues with running one device interchangeably with the other.    

   I wrote Sotishi Labs to get clarification on these questions and the following is the reply from their help desk:    

  When initializing TREZOR you will be firstly asked to set your PIN and then recovery seed (24 words). Recovery seed is the main key for the recovery process. You can recover your whole wallet with every account and transaction history if you keep your recovery seed in some safe place and available for your use.

  If you use both devices with the same recovery seed, there always will be the same status (amount, accounts, transactions) on either of them even if you use mainly the "original" device and the second one only rarely as a backup. The only possible issue might occur when both devices have different firmware, but this should not affect the accounts, amount etc..., only some specific functions which might not be supported on another device with earlier update. 

   I was also curious if the PINs needed to be the same on both devices, as it would seem logical if they were linked to a specific account, which is typical for a bank account. As it turns out each device may have it’s own unique PIN, and even so, keeping them the same is probably the preferred option for most, if only for convenience. 

    As for the PIN protection. Actually, you can have different PIN settings on both TREZOR devices with the same recovery seed. PIN protection is not related to recovery seed (basically your master key) and you need to set it up anew whenever TREZOR is initialized (this includes the recovery process). 

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 If you are new to Bitcoin an the TREZOR device in particular, here is a video that quickly explains how to set up the TREZOR device (click picture for link) 

      

           TREZOR: The Bitcoin Safe

Keywords:

Bitcoin, TREZOR, Blockchain, Modern Cryptography