Reference
Electricity tariff glossary
Edited by Rob Gibbs. Guidance reviewed: .
- BST and daylight saving time
British Summer Time is the UK clock setting one hour ahead of GMT during the warmer part of the year. Tariff windows described in UK local time can therefore keep the same clock label while their UTC instant changes.
Related: Time-of-use tariff, Unit rate
- Bill versus estimate
A bill applies the supplier’s complete account, meter and billing rules. An OctoTariffs estimate applies only the published rates, evidence window, usage assumptions and exclusions shown beside the result.
Related: Standing charge, Unit rate
- Distribution Network Operator (DNO)
The licensed company operating the local electricity distribution network that carries power from the transmission system to homes and businesses in an area.
Related: Grid Supply Point group (GSP), Meter Point Administration Number (MPAN)
Sources: Octopus Energy: Domestic energy supply terms and conditions
- Dynamic tariff
A tariff whose applicable unit price can change frequently according to a published formula or market-linked input; Agile uses a different unit rate for each half hour.
Related: Time-of-use tariff, Unit rate
- Export
Electricity sent from a property to the public grid. An export rate is a payment for eligible exported energy, not an import-cost discount.
Related: Import, Smart Export Guarantee (SEG)
- Grid Supply Point group (GSP)
One of the lettered regional groups used to associate electricity tariff rates with a location in Great Britain. OctoTariffs uses 14 groups, A to P excluding I and O.
Related: Distribution Network Operator (DNO), Meter Point Administration Number (MPAN)
- Half-hourly settlement
The process of allocating electricity consumption or export to 30-minute settlement periods so market and tariff calculations can use when energy moved, not only a cumulative meter total.
Related: Dynamic tariff, Time-of-use tariff
- Import
Electricity drawn from the public grid and consumed at the property. Import unit rates are charges, unlike export rates, which are payments.
Sources: Octopus Energy: Domestic energy supply terms and conditions
- Meter Point Administration Number (MPAN)
The identifier for an electricity supply point. It is account-sensitive information and is not needed when reporting an error on a public tariff page.
Related: Meter Point Reference Number (MPRN), Distribution Network Operator (DNO)
Sources: Octopus Energy: Domestic energy supply terms and conditions
- Meter Point Reference Number (MPRN)
The identifier for a gas supply point. It is different from the electricity MPAN and should not be sent in a public-page correction report.
Related: Meter Point Administration Number (MPAN)
Sources: Octopus Energy: Domestic energy supply terms and conditions
- Plunge pricing
An informal name for a half-hour in which an Agile import unit rate is below zero. It creates a negative unit-cost contribution for that interval before standing charges and other bill items.
Related: Dynamic tariff, Bill versus estimate
- Price cap versus tariff
Ofgem’s price cap constrains covered standard-variable domestic rates; it is not a tariff, a maximum total bill, or a benchmark for export payments.
Related: Standing charge, Unit rate
Sources: Ofgem: Energy price cap and standing charges explained
- Product code versus tariff code
A product code identifies a supplier product version. A tariff code identifies the priced fuel, register, direction and region under that product. One product can therefore have several tariff codes.
Related: Grid Supply Point group (GSP), Unit rate
- Smart Export Guarantee (SEG)
The scheme under which eligible electricity suppliers offer payments for qualifying small-scale low-carbon electricity exported to the grid.
- SMETS1 and SMETS2
First- and second-generation specifications for Great Britain smart meters. A tariff may require a suitable meter and reliable half-hourly readings; some device-control tariffs require a specific setup.
Related: Half-hourly settlement, Meter Point Administration Number (MPAN)
- Standing charge
A daily charge applied independently of how many units of energy are used that day. Comparisons should show it separately from the unit rate.
Related: Unit rate, Bill versus estimate
Sources: Ofgem: Energy price cap and standing charges explained
- Time-of-use tariff
A tariff with different prices applying at different times. Its bands may be fixed, conditional on a smart schedule, or change day by day.
Related: Dynamic tariff, BST and daylight saving time
- Unit rate
The price charged or payment made for each unit of energy, usually shown here in pence per kilowatt-hour. It does not include the standing charge.
Related: Standing charge, Import, Export
Sources: Ofgem: Energy price cap and standing charges explained