[5] Throughout the years, the local Church was administered by various ecclesiastical jurisdictions centred in Labuan, Jesselton, Kuching and Miri, cities in neighbouring Malaysia.

[6] Until 1936, when a church was established in Kuala Belait, the vicariate primarily was an outstation of Our Blessed Sacrament Parish in Labuan.

Sim was appointed the first apostolic vicar, carrying the dignity of a titular bishop: his episcopal ordination took place in January 2005.

[10] The vicariate is a territory under the ecclesiastical authority of an apostolic vicar, who sits on the Catholic Bishops' Conference of Malaysia, Singapore and Brunei.

[16] During the COVID-19 pandemic, the vicariate introduced livestreaming of Mass for the faithful to participate in a virtual capacity during lockdown measures.

[17][18] The Society of St Vincent de Paul is active in the vicariate, where they gather monetary and physical aid and distribute to those in need.