Just the name: New Zealand stopped being a colony and became a dominion. There was no tangible political or legal shift.
From this date, the premier was styled as prime minister, and the term ‘Members of Parliament’ replaced ‘Members of the House of Representatives’.
Not a bit. Few New Zealanders actually wanted greater independence from Britain in 1907. Race sentiment, language, culture, defence and trade links bound most New Zealanders closer to the wider ‘Britannic world’, then at the height of its prestige.
Those feelings persisted through the first half of the 20th century, even though dominion status evolved as a label for the constitutional position of the former self-governing colonies (and the Irish Free State). In 1926, after pressure from the Irish, South Africans and Canadians, the Balfour Declaration stated that Britain and the dominions:
Are autonomous Communities within the British Empire, equal in status, in no way subordinate one to another in any aspect of their domestic or external affairs, though united by a common allegiance to the Crown, and freely associated as members of the British Commonwealth of Nations.
New Zealand's prime minister, Gordon Coates, called this a ‘poisonous document’. Until 25 November 1947, New Zealand refused to ratify the Statute of Westminster 1931, which removed London’s right to legislate for the dominions unless they asked it. The Constitution Act 1986 finally removed the last faint provision for the British Parliament to make laws for New Zealand.
Dominion status ended with a whimper. In 1945, when the country joined the United Nations, it was simply called ‘New Zealand’. In January 1946 officials were told to change their letterheads to say ‘New Zealand’ – but not to publicise the change.
In 1953 the official style was changed to the ‘Realm of New Zealand’. The term ‘dominion’ hung on in the names of institutions (the Dominion Museum was not renamed the National Museum until 1972), businesses and in the constitutions of clubs and societies. The name still survives in the title of the Dominion (now Dominion Post) newspaper, first published in Wellington on 26 September 1907.
Although the term is no longer used to describe New Zealand, the 1907 royal proclamation of dominion status has never been revoked and remains in force today. New Zealand’s formal title may therefore still include the term 'dominion'. Generally, however, the country is today known as the Realm of New Zealand.