Key terms and issues explained

Mae’r dudalen yma ar gael yn Gymraeg.

On this page you will find a range of key terms explained for business energy. Please click on a letter below to be taken to a list of terms and on "show" to read the explanation.

Annual Bill

The amount that a customer would have to pay for gas, electricity or both over one whole year.

Annual Statement (also known as Annual Gas/Electricity Summary)

A written document that suppliers must provide to each customer, each year. The Annual Statement contains a range of key tariff information, including tariff name, consumption over the previous 12 months and estimate of annual cost for the next 12 months.


Describes the interest rate for a whole year, rather than just a monthly fee or rate, as applied on a loan, mortgage, credit card etc. It is a finance charge expressed as an annual rate.

Authority, The

The Gas and Electricity Markets Authority, sometimes referred to as GEMA, that acts as our governing body.

Automatic Contract Rollover (Auto-Rollover)

Where, due to the terms of a contract, a supplier has the ability to extend the duration of an existing Fixed Term tariff or apply a new Fixed Term tariff without a consumer’s positive assent.