To transfer existing ISA funds from elswhere, you need to get a transfer form from your new provider (you should be able to print one from their website or ask for it in the branch). You need to fill in you details (nama, address etc.), number of the ISA account you want to transfer your money to and account number of the ISA you want to transfer (all of this is on the statements). You need a separate form for each ISA account you wish to transfer. When you fill it you need to send he form/s to the bank (that holds the account you want to transfer from them). They will calculate the interest due, close the account and send the form you filled in together with the payment to your new bank, so it can be paid into your new account.