Could it be that someone with a similar address or postcode has recently moved too and has made a mistake when setting up accounts? For a water bill I could see this – you move into a new place, call the water company who say there is an existing account so you stop that one and set up a new one – but you’ve got one part of the address wrong.
Could also be a letting agent (I once had a letting agent set me up with two electricity accounts when I moved on – one for my flat and one for another flat who knows where as they’d obviously just used the same name and address for two different meters/accounts).