How can I change my address
Buy a new house and move into it is typically the way of obtaining a new address.
If you mean your email address, just login to your account at https://account.bulb.co.uk (or click ‘Sign in’ in the top right corner), select ‘Account & Tariff Info’ and then ‘Change contact details’ on the left.
If you are moving house (and will have nothing to do with the current address), again just login to your account and next to your address on the main page there should be a picture of a lorry and the text ‘Moving home’ (on the right) - just go through those steps and Bulb will start closing your account on that date and ensure you won’t be responsible for the bills for that property going forwards (if you want Bulb at your new property, you’ll just need to sign up again with that address - if you use the same email address/password when you sign up, everything should be associated under the same login for simplicity).
If you are moving house, but will still responsible for bills for the old property (for example, you pay your parents utilities bills are they are retired and you are on a good wage, but you are moving to your own property), then it’s a slightly tricker situation. I’m guessing you can just get away with signing up to Bulb using your new address (as above) and keep both accounts active - but in the extremely unlikely event Bulb needs to send you postal mail, it may go to your old address - if this is a concern, please contact Bulb directly via email or phone (see https://help.bulb.co.uk/hc/en-us/articles/115001240291-How-can-I-get-in-touch-with-Bulb- ) and they’ll be able to help.
If I’ve misunderstood your question, my apologies (I’m just another Bulb customer like yourself), but if you rephrase it, I’ll give it another go