The overlapping continental shelf entitlements of Ireland and the United Kingdom were first delimited in 1988 through a bilateral boundary agreement. As originally defined, the boundary was composed of two lines, A and B. Line A was formed by 94 points and extended for 502 nautical miles, while Line B contained only 35 points but extended for 634 nautical miles.

A 1992 Protocol, supplementary to the 1988 Agreement, extended Line A northward by an additional 11 nautical miles. This was followed by a 2001 Exchange of Notes that provisionally delimited an additional northward extension in an area of continental shelf where Ireland and the United Kingdom wished to construct a natural gas pipeline. A 2013 Agreement between the two States finally revised portions of the 1988 boundary and finalized the 2001 provisional delimitation. The two States now have a multipurpose maritime boundary that delimits their overlapping exclusive economic zone and continental shelf entitlements.