Constitutional Amendment

A constitutional amendment is a formal change to the text of the written constitution of a nation or state.

Most constitutions require that amendments cannot be enacted unless they have passed a special procedure that is more stringent than that required of ordinary legislation. Examples of such special procedures include super-majorities in the legislature, or direct approval by the electorate in a referendum, or even a combination of two or more different special procedures. A referendum to amend the constitution may also be triggered in some jurisdictions by popular initiative.

Australia and the Republic of Ireland provide examples of constitutions requiring that all amendments are first passed by the legislature before being submitted to the people; in the case of Ireland, a simple majority of those voting at the electorate is all that is required, whereas a more complex set of criteria must be met in Australia (a majority of voters in a majority of states is also necessary). Switzerland has a similar procedure to Australia's.

Denmark provides an example of multiple special procedures that must be followed. After an amendment has been approved by parliament, a general election must be held; the new parliament must then approve the amendment again before it is finally submitted to a referendum. There is also a requirement that at least 40% of eligible voters must vote at the referendum in order for an amendment to be validly passed.

The special procedures for the amendment of some constitutions have proven to be so exacting that either few (Australia) or no proposed amendments (i.e. Japan) have been passed over a period of several decades. In contrast, the constitution of the US state of Alabama has been amended over 800 times since 1901.