From the very start, CEX.IO has been supporting SegWit, a solution aimed at fixing the problem of the blockchain size limitation. As you know, SegWit has been activated on August 24, 2017, and we congratulate the network with this important update, on behalf of CEX.IO.
How SegWit Affects CEX.IO Users
First and foremost, Bitcoin addresses have changed together with the SegWit activation. Thus, the new addresses start with a 3, and you can check yours when logging in to your CEX.IO account and navigate to the Finance section.
There is no need to worry, as your old BTC address is still working, and all the funds deposited to the old address will be credited to your account without any issues. However, we highly recommend using the new addresses.