Choice-Based Lettings (CBL) is a type of social housing system in the United Kingdom that enables applicants to express their housing preference and rank them in order of preference. It is a type of letting system that is based on choice and is aimed at providing more choice and control to people looking for social housing. CBL allows eligible applicants to choose and bid for available social housing through an online system. The purpose of CBL is to make the process of finding a suitable home easier and more efficient, while also giving applicants greater control over the process. CBL also aims to make the allocation of housing more fair and transparent by allowing applicants to express their preferences and prioritise them accordingly. The scope of CBL is to ensure that applicants are able to find suitable housing that meets their needs and preferences, while also providing a more transparent and accountable system for allocating social housing.