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.

In-area customers

Customers of an electricity supplier who are located within  the supplier's original ex-PES region.

Incumbent suppliers

See ex-PES suppliers.


An organisation that can help consumers to switch energy tariffs.