how big is it?
there is another spider that looks like that which you can find around your house quite frequently that is not a redback! not sure on its name though.
Male redback, poisonous. I'd be calling pest control asap - especially if you have any furry pets or children around the house. If there's a male around there is certin to be a female or two.
it is not a female redback, and it certainly not a male redback!
... looks like Steatoda paykulliana, but could be any Steatoda species, they are commonly called cupboard spiders...
Google male redbacks. They're just as toxic as the females. Because their fangs (on either male or female) are tiny, most of their bites are effectively 'dry bites', thier venom acts directly on the nerves, resulting in release and subsequent depletion of neurotransmitters.
All round nasty.