See 'Registration'. The incumbent supplier has the right to object to registration if the current contract has not reached its end date or there is debt associated with it.

Off Peak
Period of low production or demand.

Off Shore
Normally used to refer to the North Sea oil and gas fields.

An indication of willingness to sell at a given price, the opposite of 'Bid'.

Office for the Regulation of Electricity and Gas (Ofreg)
The regulatory body for the gas and electricity markets in Northern Ireland.

See 'Closing Out'

An emissions reduction, commonly resulting from a project undertaken in the developing world, which has been sold to compensate for emissions elsewhere. Offsets are commonly used to net off corporate emissions so that an organisation can claim to be carbon neutral.

Gas consumed by a site or customer.

A market with few sellers but many buyers.

Open Order
A resting order that is good until it's cancelled.

Open Outcry
A trading system in which members trade verbally on a trading floor.

A derivative instrument which provides the right to buy or sell a commodity at a given price sometime in the future. The buyer can then choose whether or not to exercise the option depending on market conditions and investment strategy.

Contracts which give the purchaser the right, but not the obligation, to buy or sell electricity at a certain price on or before an agreed date.

Organisation of Petroleum Exporting Countries (OPEC)
An intergovernmental organization of twelve developing countries made up of Algeria, Angola, Ecuador, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, the United Arab Emirates, and Venezuela.

Out of Contract
Terms of supply contract applied when a existing supply contract lapses either without a replacement or through default. Typically incorporate prices much above market levels to incentivise customer to negotiate a full commercial agreement.

An option that has no intrinsic value. A put option is out-of-the-money when its strike price is below the value of the underlying futures contract. A call option is out-of-the-money when its strike price is above that of an underlying futures contract.

Communications method used to communicate with a meter i.e. GSM, modem, packnet.

Over the counter (OTC)
Security transactions not performed on a stock exchange.

Over-run Gas
Gas taken by a consumer after a supply contract end date, normally attracting higher charges.