Bill Potts lived in a flat in Bristol (PROSE: The Shining Man) with her foster mother, Moira.
During Christmas 2016, Moira told Bill she had found pictures of Bill's mum on the back of the cupboard, and that she wasn't even aware they had these photos.
Later, Bill returned to her flat to hear the shower running. When she received a call from Moira, she was surprised to hear no one was staying over. Upon investigating further, she found out that the sentient oil had followed her to her flat. (TV: The Pilot)
A shadow version of Bill Potts brought a girl called Penny to her flat to have a drink with her. However, the Twelfth Doctor landed his TARDIS here, distrubing their date. The real Bill was making tea when the Doctor phoned her. (TV: Extremis) It would similarly occur when the real Bill invited the real Penny inside. (TV: The Pyramid at the End of the World)
