The British government made one change before the Bill was passed. The Chief Justices of the colonies wanted the right to appeal decisions of the High Court to the Privy Council on constitutional matters. They were worried that the limits of the powers of the Commonwealth or States could be changed by parliament. The British Parliament passed the "Commonwealth of Australia Constitution Act" in 1900. Western Australia finally agreed to join the Commonwealth in time for it to join the Commonwealth of Australia, which officially began on 1 January 1901.
In 1990, the Public Records Office in London loaned the original copy 1900 of the "Commonwealth of Australia Constitution Act" to Australia. The Australian government wanted to keep the copy. The British parliament agreed by passing the "Australian Constitution (Public Record Copy) Act 1990".
Although Federation made Australia independent of Britain, legally the Commonwealth was a creation of the British Imperial Parliament, through the "Commonwealth of Australia Constitution Act" 1900 (Imp), which applied to Australia. As a result, there was continued uncertainty as to whether British Imperial laws still applied to the Commonwealth. This was fixed by the "Statute of Westminster 1931", adopted by the Commonwealth via the "Statute of Westminster Adoption Act 1942". The Statute of Westminster freed the Dominions, including the Commonwealth, from Imperial laws and controls. Legally, this is the moment of Australia's national independence.
However, British laws were still more important in Australian states. This was fixed by the "Australia Act 1986", which was passed by the parliaments of Australia, the United Kingdom, and each of the states. This law stopped the British Parliament's power to make laws over Australian states. It also stopped appeals from the Australian courts to the Judicial Committee of the Privy Council. As this was a very important document, Queen Elizabeth II travelled to Australia to sign the proclamation of the law.
One result of these two laws is that Australia is now a fully independent country. The Constitution is now different from the original Act, as the Australian people can change the Constitution, by referendum. However, the original Act remains on the UK's law book with a note saying, "The Constitution is not necessarily in the form in which it is in force in Australia". Even if the United Kingdom Parliament were to remove the "Commonwealth of Australia Constitution Act 1900", it would have no effect on Australia.
The "Commonwealth of Australia Constitution Act 1900" (Imp) contains a Preamble, and nine sections. Sections 1– 8 are the laws to set up the Commonwealth. Section 9, starting with the words "The Constitution of the Commonwealth shall be as follows ...", contains the Constitution of the Commonwealth of Australia. The Constitution itself is in eight chapters, with 128 sections.
Chapter I sets up the Parliament of Australia. This has three parts:
Section 1 says that legislative power belongs to the Parliament. It is the most powerful part of government.
Part II of Chapter 1 is about the Senate. Senators are to be "directly chosen by the people of the State", voting as a single electorate. Each State is to have the same number of senators. Currently, there are 12 senators for each State, and 2 each for the mainland territories, the Northern Territory and the Australian Capital Territory.
Part III of Chapter 1 is about the House of Representatives. Section 24 says the House must have twice as many members as the Senate, each elected by a single electorate. This is called the 'Nexus'. It designed to prevent swamping of the senate's power in the case of a joint sitting (see Section 57 below). The number of electorates in a State is to be based on its share of the national population.
Part IV of Chapter 1 says who can vote, who can be elected to the parliament, how much members can be paid, parliamentary rules and related matters.
Part V of Chapter 1 is about the powers of the parliament. Section 51 deals with powers of the Commonwealth parliament and are called "specific powers". There are also "concurrent powers", and both the Commonwealth and the States can make laws on these subjects. Federal law is more important if the laws are different (Section 109). Of the thirty-nine parts of section 51, a few have become very important in deciding how much power the Commonwealth government has in law. These include the Trade and Commerce Power, the Corporations Power and the External Affairs Power. Section 52 deals with powers that belong only to the Commonwealth parliament. States cannot make laws on these subjects.
Chapter II sets up the executive branch of government. Executive power is to be exercised by the Governor-General, advised by the Federal Executive Council. The Governor-General is the commander in chief. He or she may appoint and dismiss the members of the Executive Council, ministers of state, and all officers of the executive government. These powers, along with the powers to dissolve (or refuse to dissolve) parliament (Section 5, Section 57), are termed "reserve powers". The use of these powers is by convention. Generally, the Governor-General acts only on the advice of the Prime Minister. There has been only one instance of the Governor-General not taking the Prime Minister's advice. Governor-General Sir John Kerr, acting on his own, dismissed Prime Minister Gough Whitlam in the 1975 Australian constitutional crisis.
Reserve powers in all Westminster nations are only "extremely" rarely exercised outside of the understood conventions. However, in contrast with the constitutions of other Commonwealth Realms such as Canada, which formally grant extensive reserve powers to the Monarch, even the formal powers of the Queen of Australia are extremely limited, and most powers can be used only by the Governor-General.
Section 68 says that the Command in chief of Australia's naval and military forces "is vested in the Governor General as the Queen's representative". The Commander in chief of the Australian Defence Force is now Her Excellency Quentin Bryce as the Governor General of Australia. The Queen of Australia is not in command of the military.
Chapter III sets up the judicial branch of government. Section 71 gives judicial power to a "Federal Supreme Court" called the High Court of Australia. The Parliament can also make new federal courts or give other courts federal powers. Such courts, called "Chapter III Courts", are the only courts that can use federal judicial power. Sections 73 and 75-78 outline the original and appellate jurisdiction of the High Court. Section 74 explains how an appeal can be made to the Queen in Council. Section 79 allows Parliament to limit the number of judges able to exercise federal jurisdiction and section 80 guarantees trial by jury for indictable offences against the Commonwealth.
Chapter IV deals with finance and trade in the federal system. Section 81 says that all Commonwealth revenue shall form the Consolidated Revenue Fund. Parliament can make laws as to the how its money is spent (Section 53). Unlike most other powers of the parliament, laws made under this power cannot usually be challenged. Section 90 gives the Commonwealth exclusive power over duties of custom and excise.
Section 92 provides that "trade, commerce, and intercourse among the States shall be "absolutely free"". The precise meaning of this phrase is the subject of a considerable body of law.