Start by checking the billing period, meter readings and whether the bill is based on an actual or estimated reading. Your total usually includes electricity usage, a daily supply charge, GST and any discounts, concessions or solar feed-in credits that apply under your plan. Compare your usage in kilowatt-hours (kWh) with earlier bills, and check the tariff, rates and payment due date. If something looks wrong, contact your retailer first; you can also compare plans through an impartial government comparison service such as Energy Made Easy.