British National (Overseas), abbreviated BN(O), is a class of British nationality associated with the former colony of Hong Kong. The status was acquired through voluntary registration by individuals with a connection to the territory who had been British Dependent Territories citizens (BDTCs) before the handover to China in 1997. Registration for BN(O) status was limited to the 10-year period preceding the transfer as a transitional arrangement for colonial subjects; current residents cannot newly acquire this nationality. BN(O)s are British nationals and Commonwealth citizens, but not British citizens. They are subject to immigration controls when entering the United Kingdom and do not have automatic right of abode there or in Hong Kong, but all BN(O)s would have had permanent resident status in Hong Kong when they acquired this nationality. Following the Chinese government's imposition of controversial national security legislation on Hong Kong, the UK has allowed BN(O)s and their dependent family members to apply for renewable five-year residence visas since 31 January 2021. This nationality gives its holders favoured status when they are resident in the United Kingdom, conferring eligibility to vote, obtain citizenship under a simplified process, and serve in public office or government positions. There are an estimated 2.9 million BN(O)s; about 708,000 of them hold active British passports with this status and enjoy consular protection when travelling abroad. However, the Chinese government does not recognise these passports as valid travel documents and restricts BN(O)s from accessing British consular protection from diplomatic missions located in Hong Kong and mainland China. Background Hong Kong was a British colony from 1842 until its transfer to China in 1997. The territory initially consisted only of Hong Kong Island and was expanded to include Kowloon Peninsula and Stonecutters Island in 1860. All of these areas were ceded in perpetuity to the United Kingdom by the Qing dynasty after the Opium Wars. Britain negotiated a further expansion of the colony to include the New Territories in 1898, which were leased (rather than ceded) from Qing China for a period of 99 years. As the end of the lease drew closer, Hong Kong's future was uncertain. Because most of the territory's industry was developed in the New Territories, separating the leased area and returning only that part of the colony to China was economically and logistically infeasible. The colonial government could not grant new land leases in the New Territories past 1997, causing concern among