In the context of government and law, a formal amendment is "an addition or alteration made to a constitution, statute, or legislative bill or resolution," according to the Encyclopedia Britannica. The U.S. Constitution prescribes four possible methods of making a formal amendment to the Constitution, though of these four methods one has been used only once, and two have never been used. In the United States, a formal amendment to the Constitution requires a proposal, approval and ratification process.
The most often used method of formally amending the U.S. Constitution begins with each house of the U.S. Congress approving the proposed amendment in the form of a bill with a two-thirds majority vote. Once both the Senate and House of Representatives pass the amendment, the proposal is sent to the state legislatures for approval. Three-fourths of the states are required to ratify the amendment.
The first 10 amendments are commonly known as the Bill of Rights.
Twenty-seven amendments have been added to the Constitution. Six amendments are pending state ratification. Thousands have been proposed but not passed.
The authority to amend the Constitution is derived from Article V of the Constitution.
The Constitution is said to have informal amendments, which means that because of circumstances or judicial interpretation, the meaning of the Constitution is altered.