Reducing your consumption is actually more important than identifying savings that could be made by simply switching supplier. You can save money with a cheaper tariff for the duration of your contract, which is good. However, lowering your total consumption has a long-term effect on your overall energy costs, not to mention the carbon savings.
Our energy review provides information about measuring energy and smart metering. Research from the Carbon Trust shows that by simply monitoring energy use in the workplace, companies could save over 12.3% on their bills.