Smallest and least populous of all countries forming the United Kingdom, Northern Ireland is located on the other side of the Irish Sea. Even though it is not physically sharing an island with the rest of the United Kingdom countries, it is just as important a part. Not surprisingly, it is also a part of the same phone network and follows the same rules, with landlines assigned specific prefixes that denote the area they are physically located in. And since landlines are still very much in use, albeit in a smaller group, finding the right area code quickly should still prove to be useful and important. Using our website you can find anything there is to find out about area codes, you can also use the map to look them up.