From what I understand, when communicating with your energy supplier who already has your name but then tries to communicate with you as occupier it is okay to cross out occupier and use your name when corresponding. however, if they don't have your name and try to send correspondence then return to sender. There is an occupier loophole they try to use to get warrants etc. I tested Peter's bot and this is the response. It is advisable not to sign for a letter addressed to "the occupier" as it may imply acceptance of the contents or acknowledgment of the claim. Instead, you should consider returning the letter to the sender marked "not at this address" or "refused." This action helps to maintain your position and avoid any unintended implications regarding the claim.