when travelling to either place and are not treated identically to British citizens when entering other countries. The Joint Declaration allows continued use of foreign passports as travel documents post-handover, but the Chinese and Hong Kong governments have not allowed BN(O) passports to be used for immigration clearance since 31 January 2021. United Kingdom British Nationals (Overseas) are subject to immigration controls and have neither the right of abode nor an automatic right to work in the United Kingdom. They are ineligible for the Registered Traveller service, which enables expedited clearance through British immigration, despite the eligibility of Hong Kong Special Administrative Region passport holders. BN(O)s are required to pay an immigration health surcharge to access National Health Service benefits when applying for a visa to remain in the UK for longer than six months and do not qualify for most welfare programmes. Hong Kong and China The vast majority of British Nationals (Overseas) are ethnically Chinese and were automatically granted Chinese nationality at the transfer of sovereignty in 1997. Individuals who hold Chinese nationality concurrently with any other nationality, including BN(O) status, are treated solely as Chinese nationals under Chinese nationality law. Consequently, most BN(O)s do not have access to British consular protection while in Hong Kong, Macau, or mainland China. Additionally, BN(O)s who are Chinese nationals must use a Mainland Travel Permit to enter mainland China. Until 31 January 2021, BN(O)s were able to use their UK passports for immigration clearance in Hong Kong and to seek consular protection from overseas Chinese diplomatic missions. Since that date, the Chinese and Hong Kong governments have prohibited the use of BN(O) passports as travel documents or proof of identity. BN(O)s who do not possess Chinese (or any other) nationality are required to use a Document of Identity for Visa Purposes for travel. This restriction disproportionally affects ease of travel for permanent residents of South Asian ethnicity, who were not granted Chinese nationality in 1997. As an additional consequence, Hongkongers seeking early pre-retirement withdrawals from the Mandatory Provident Fund pension scheme may not use BN(O) passports for identity verification. BN(O)s are barred from registering same-sex marriages at the British Consulate-General, Hong Kong. Consular same-sex marriages under UK law are contingent on local authority approval, which the Hong Kong government has explicitly denied. Conversely, Chinese authorities have not prohibited these marriages from taking place in mainland China. Although registration for BN(O) status