apple id is different on pc and phone

Hi, I have an iphone 5s and recently bought the 7s. I now want to store and backup onto icloud from the 5 so I can download to the 7. Using the 5 and my pc I tried to change the passwords, email address and recovery email. I can now log on to my apple account via the pc. However when I try to log onto icloud on the phone it gives me the old "ID" address. How do I get the phone to use the new log in "ID" as stored in my account. Thank you. C