Following the 1948 Commonwealth Prime Ministers ' Conference in London where the future of nationality law within the Commonwealth was discussed , New Zealand 's parliament passed the '' British Nationality and New Zealand Citizenship Act 1948 '' which established New Zealand citizenship , coming into force on 1 January 1949 . The United Kingdom 's own British Nationality Act 1948 came into force on 1 January 1949
1948 Commonwealth Prime Ministers ' Conference
1948 Commonwealth Prime Ministers' Conference
New Zealand nationality law