Best answer by woz
Sadly as they say (whoever they are?) You cant take it with you! That applies to ANY supplier by the way.
You'll need to complete the move out section in the app/online (in accounts section). You'll eventually get a final bill. You'll need to submit meter readings a couple of days before you leave (take photos too for your own records).
Once you move into the new place you can then switch into PP, you'll be a deemed customer of whoever the supplier is until the switch happens and they will issue a final bill eventually.
Good luck with the move.