To link a bank account, go to Settings -> Bank accounts and fill in the details of your bank account.
Please note that you can only link bank accounts in your name. We do not support third-party transfers.
NB: you need to agree with the UK Banking Terms and Conditions before being able to link a GBP bank account. In order to to this, please click on the Deposit button next to your GBP account, read thought the T&C and agree with them.