Energy Glossary

Available capacity (kVA)

The amount of power your site is contracted to be able to draw, measured in kilovolt amperes. You pay a monthly capacity charge for it whether you use it or not, and an excess charge if you go over. Sites often carry capacity agreed for equipment that has since been replaced or removed.

Broker commission (uplift)

How most energy brokers are paid: a small amount added to the unit rate by the supplier and passed to the broker, rather than a fee billed to you. It is why a comparison can be free to the business. Ofgem expects a third party intermediary to disclose it, so ask any broker what their commission is and how it is charged.

CCL (Climate Change Levy)

A government tax on business energy, charged per kWh on top of your unit rate and shown as its own line on the bill. Charities and some very low usage supplies are exempt or pay a reduced rate, and energy intensive sites can claim relief through a Climate Change Agreement.

Change of tenancy (COT)

The process of putting the meter into your name when you take on a premises. Until it is done you are usually billed on deemed rates, so it is worth completing on day one rather than after the first bill arrives.

Contract end date

The date your current fixed term deal expires. Miss it and you roll onto out of contract rates, or onto whatever your supplier's rollover terms allow. It is the single most useful date to have in your diary.

Deemed rate

The default tariff a supplier applies when there is no contract in place, for example after a fixed term ends or when you move into a premises. Deemed rates are the most expensive way to buy energy, commonly 40 to 60% above a negotiated tariff. There is no exit fee for leaving one, so a site on deemed rates can move as soon as a new contract is agreed.

DUoS (Distribution Use of System)

The charge for using the local network that brings power from the grid to your meter. On a small supply it is bundled into your unit rate. On a half-hourly supply it can appear separately and varies by time of day.

Energy broker

A company that compares the market and arranges a supply contract on your behalf. A broker has access to rates that are not published, and is paid by the supplier rather than by you. See also TPI.

Estimated reading

A bill calculated from a projection rather than an actual meter reading, usually marked with an E. A run of estimates ends in either a large catch up bill or a credit sitting with the supplier, so submit a reading on the same date each month if your meter is not read remotely.

Export tariff and feed-in tariff

What you are paid for electricity your site generates and sends back to the grid, typically from solar panels. The old Feed-in Tariff scheme closed to new applicants in 2019 and was replaced by the Smart Export Guarantee, under which suppliers set their own export rate. Export rates vary widely between suppliers, so if you generate on site it is worth comparing supply and export together.

Fixed rate tariff

A contract where the unit rate and standing charge are locked for the term, usually one to five years. It gives you a number you can budget against and protects you from price rises during the term, but it will not fall if the wholesale market does.

Half-hourly (HH) meter

A meter that records consumption in 48 slots a day and sends the data automatically. It is mandatory above roughly 100,000 kWh a year and common on any larger supply. The data shows your true peak and your overnight baseload, which is what makes time of use pricing worth looking at.

kVA (kilovolt-ampere)

The unit apparent power is measured in, used for the capacity of a supply and for maximum demand charges. Staggering the start up of large equipment keeps the peak kVA down and can reduce what you pay.

kWh (kilowatt-hour)

The standard unit of energy, and the thing your unit rate is priced against. One kWh is a thousand watts drawn for an hour. Every piece of equipment on your site has a rating in kilowatts, so hours of use multiplied by that rating is roughly what it costs you to run.

Letter of authority (LOA)

A short signed document letting a broker speak to your supplier about your account, obtain your consumption data and request rates. It does not commit you to switching or to anything else.

Micro-business

In energy terms, a business with fewer than ten employees and turnover or a balance sheet under €2 million, or one using less than 100,000 kWh of electricity or 293,000 kWh of gas a year. Micro-businesses have extra protections under Ofgem rules, including limits on rollover and clearer contract end notifications.

MPAN (Meter Point Administration Number)

The unique reference for an electricity supply point, a 21 digit number printed on your bill and often on the meter. Quotes are priced against it, so a supply with several meters has several MPANs.

MPRN (Meter Point Reference Number)

The equivalent unique reference for a gas supply point. Shown on your gas bill and needed for any gas quote.

Multi-site contract

One agreement covering several premises, usually with a single end date and one set of rates. It removes the problem of branches quietly drifting onto different contracts and different deemed rates, and larger portfolios can be priced more keenly than the same sites bought one at a time. Sites can be added to most multi-site agreements as you open them.

Non half-hourly (NHH) meter

A meter that records a running total read periodically rather than in half hour slots. Most small and medium sites are non half-hourly, sometimes with automated meter reading fitted so the readings are sent remotely.

Out-of-contract rate

The rate you are moved to when a fixed term ends and you neither renew nor switch. Like a deemed rate it is well above anything you would be quoted, and like a deemed rate it carries no exit fee, so you can leave it as soon as a new contract is in place.

Rollover

A clause that automatically puts you onto a new fixed term when your current one ends, usually at a rate you would not have agreed to and often for another twelve months. Ofgem restricts rollover for micro-businesses, but plenty of contracts still contain one. Check the notice window in your terms and diarise it.

Standing charge

A fixed daily amount per meter for being connected, payable whether you trade that day or not. Business standing charges commonly run from about 25p to 60p a day, so roughly £90 to £220 a year per supply. A site with several small meters pays it several times over.

Supplier

The company that sells you the energy and sends the bill. It is separate from the network operator that owns the cables and pipes, which is why switching supplier never affects the physical supply.

TNUoS (Transmission Use of System)

The charge for using the national high voltage transmission network. Bundled into the unit rate on smaller supplies and itemised on half-hourly ones.

TPI (third party intermediary)

Ofgem's term for a broker, consultant or comparison service acting between a business and its supplier. A TPI should tell you how it is paid, which suppliers it can access, and whether the rates it shows include its commission.

Unit rate

The price per kWh, and the main variable part of your bill. For most small business supplies it sits somewhere around 25 to 35p/kWh for electricity and 6 to 12p/kWh for gas. A rate well above that usually means the contract has lapsed rather than that your site is unusual.

Variable rate tariff

A tariff whose unit rate can move during the term, usually tracking wholesale prices. Cheaper than a fixed rate in a falling market and painful in a rising one, so it suits a business that can absorb the swing.

Want these terms in context? Read understanding your business energy bill, or see how we estimate savings.