Distribution network operator

[1] In Great Britain, distribution network operators are licensed by the Office of Gas and Electricity Markets.

There are fourteen licensed geographically defined areas, based on the former area electricity board boundaries, where the distribution network operator distributes electricity from the transmission grid to homes and businesses.

Historically such cabling would have been maintained and sealed by electricity boards that preceded the DNOs, and different DNOs supplying buildings of different sizes and conditions, may choose to adopt the wiring in the building or to insist that an independent BNO is appointed.

[3] Unlike a DNO or an IDNO, BNOs may be exempted from any licensing requirement by schedules 2 and 3 of The Electricity (Class Exemptions from the Requirement for a Licence) Order 2001[4] and this allows those responsible for the building network (such as a housing association) to employ any suitable electrical contractor on an ad-hoc basis.

LDCs normally buy their power from larger companies, sometimes ones dedicated solely to wholesale supply.