A Basic meter (also referred to as an Accumulation meter or Single rate meter) keeps track of the total electricity usage at your house from a start read date to an end read date, this is for a 3 month period. These meters cannot distinguish when the energy is used (ie time of day) so customers will be charged a flat rate for the total usage of kWh used. There are also meters that measure usage every 30 minutes and records it. These are called Interval meters or Time of Use meters.
The Energy Network Distributor must visit your property to take a meter read of the total energy usage over the 3 months (or since the last meter read). This figure, once validated is provided to your energy retailer to use to generate a bill.