Moving into a flat

I’ve had a look under the help section but nothing is quite right - I’m not moving as an existing account holder, or moving into a new build. I’m moving into a flat as a new customer with no existing account, I don’t pay the bills at my current property. I was hoping I could sign up and enter my move in date to start my account from then, but do I need to wait until I’ve moved in before registering?

You need to move in and create an account with whoever provides electric for the flat. Then you can start a switch.

The problem could be that the new home already has a supplier with the current tenant and they have to continue paying until they move out. If you register for a certain move in date and it changes the old tenant would then be paying Bulb (possibly).
I would move in with whoever the supplier currently is and then switch. Bulb will move you from the old to them in 21 days so you wouldnt lose much.
You could also contact Bulb on Monday and discuss.