A time-of-use tariff charges different rates depending on when you use electricity, usually with higher peak prices and cheaper off-peak periods. The times and rates vary by retailer, distributor and state, and you will generally need a smart meter to be billed this way. It may suit households that can shift activities such as washing, heating or charging an electric vehicle to cheaper periods, but savings are not guaranteed because peak use can cost more. Check your retailer’s fact sheet and compare estimated annual costs using the relevant government comparison service before switching.