Towards achieving monetary stability, the Central Bank also conducts monetary operations through the issuance of BDCB Islamic Bills (I-Bills) and Overnight Standing Facilities (OSF) to ensure sufficient liquidity for the smooth functioning of the domestic banking system. The design of these instruments and operations, in relation to its framework, are strictly aligned with the Currency Board principles.

As part of the Central Bank’s continued efforts to develop a more efficient money market for Brunei Darussalam, the two-week BDCB I-Bills was launched on 22 October 2020 - based on the Syariah concept of Wakalah bil Ujrah. The BDCB I-Bills aim to support liquidity management for the banks and the Islamic trust fund as primary investors and simultaneously expand the list of money market instruments available to BDCB and the domestic financial sector.

To provide banks with wider liquidity management options, a 4-week tenor was introduced, in addition to the 2-week tenor, beginning January 2025. With this, the Central Bank issues the 2-week tenor every fortnight and the 4-week tenor every four weeks.