On August 1st, a group of users and some businesses are planning to implement a non-compatible upgrade to the network, raising the blocksize limit to 8MB and removing SegWit. As this upgrade does not have a wide backing of the network, this “hard fork” would split the Bitcoin network in two.

As a result, we will be left with the Bitcoin with activated SegWit (through BIP91/BIP141) and its clone, dubbed Bitcoin Cash.
As this is a chain-split, Bitcoin Cash will share its entire transaction history with Bitcoin up until the point of the split, with the history diverging after the split. This means that for whatever amount of bitcoins you had before the split, you will end up having that same amount of Bitcoin Cash.

Moreover, as Bitcoin and Bitcoin Cash essentially become two separate currencies, they will be independent of each other. You will be able to spend your bitcoin cash without spending bitcoin.
This article assumes you own your private keys. With TREZOR, your private keys are in the safest place possible — in your device and nowhere else.
So what do you have to do to gain access to your Bitcoin Cash coins? Right now, nothing. Your action will be required after August 1st, and only if you want Bitcoin Cash.*

What do I need to do to claim my Bitcoin Cash?