The proposed move by Dublin-based energy firm Airtricity into the domestic electricity market in Northern Ireland will end the monopoly of NIE Energy.
It is one of the last areas of the consumer market where there is currently no competition. BBC News looks at the scale of choice for customers.
Householders have had no option other than to buy their electricity from NIE, which is owned by Bahrain-based Arcapita.
The price that NIE Energy is able to charge is subject to regulation by the utility watchdog.
Two domestic gas providers operate in Northern Ireland and they offer their services in different areas.
Phoenix Natural Gas' network covers Greater Belfast, Lisburn and Larne.
Firmus currently supplies gas in Antrim, Armagh, Banbridge, Craigavon, Newry, Ballymena, Ballymoney, Coleraine, Limavady and Londonderry.
Both firms have plans to expand the areas in which they provide gas. However, for the time being customers who use gas are restricted to one supplier.
Competition for business in this area is considerable. While BT once held a very dominant market position, deregulation has led to a host of other companies offering choices on pricing.
There are a similar number of options for customers in the broadband market.
Switching between different providers is supposed to be simple and straightforward although some individual customers have reported difficulties in doing so.
Some customers in Northern Ireland have long complained that they pay more for their motor insurance than consumers in England, Scotland or Wales.
While there numerous companies offering insurance in Northern Ireland, they do not always offer the same deal to NI customers. Television adverts often include small print emphasising that consumers in Northern Ireland are excluded.
Insurance companies maintain that the cost of settling claims is higher in Northern Ireland, making higher prices inevitable.