I think they just have to get all the details to make sure your claim is done correctly. It's the same with most benefits I'm afraid, if you move in with someone you really become joint claimants, as you are no longer "single". So it's not just a change of address, it's a change of the claim. My advice is to take a deep breath, forget about how long it is etc and for now just fill in everything you can, even if it is just name, address etc. Then get your partner a cuppa and ask him to fill it everything he can. Then look and see what is missing, make a list and get your partner to find out. Anything you can't answer (no accounts ye