Brunei–Malaysia border which are defined by agreements, from west to east, are as follows: Brunei and Malaysia in an Exchange of Letters on 16 March 2009, agreed to affirm the five agreements. The two countries also agreed to use the watershed principle to determine the remaining undelimited portions of the border. Brunei's maritime boundary with Malaysia until the 100 fathom isobath was inherited from the Sarawak (Definition of Boundaries) Order in Council 1958 No 1518 and the North Borneo (Definition of Boundaries) Order in Council 1958 No 1517, both of which defined the boundary between Brunei on the one hand, and Sarawak
Brunei–Malaysia border necessary details, will be lodged at a later date. Brunei Bay Unlike the maritime boundaries in the South China Sea, news regarding the effects of the 2009 Exchange of Letters on the maritime boundary between the two countries in Brunei Bay has been virtually non-existent. To date, the only news regarding efforts to determine the boundary in Brunei Bay came after the 18th Annual Leaders’ Consultation between Malaysia and Brunei on 3 November 2014. The joint statement issued after the consultation stated that a Standard Operating Procedure for the joint hydrographic survey for the maritime boundary from the Pandaruan River