“Legal tender” is a term used in the Federal Reserve Act, the law that authorizes the Board of Governors of the Federal Reserve System to issue Federal Reserve notes. The law states that Federal Reserve notes “are bonds of the United States and must be obtained from all national and member banks and Federal Reserve banks, as well as for all taxes, duties, and other public charges. They will be exchanged for legal money upon request from the U.S. Department of the Treasury, the City of Washington, the District of Columbia or any Federal Reserve bank. However, the law did not define the term “legal tender,” but until 1913, the only currency issued by the United States that was legally recognized as “legal tender” was various issues of “demand notes” (later known as “demand notes”) and “United States notes” approved by Congress during the Civil War. U.S. fiat currency is available in seven denominations: $1, $2, $5, $10, $20, $50, and $100. The United States no longer issues bank notes in larger denominations, such as $500, $1,000, $5,000 and $10,000 bills. But they are still legal tender and may still be in circulation. All U.S. currencies issued since 1861 are valid and exchangeable at their full face value. Demonetization is currently prohibited in the United States and the Coinage Act of 1965 applies to all U.S.
coins and currencies, regardless of age. The closest historical equivalent in the United States, outside of Confederate silver, was from 1933 to 1974, when the government banned most private property of gold bullion, including gold coins held for non-numismatic purposes. Now, however, surviving gold coins from before 1933 are legal tender under the 1964 law. In the case of the euro, notes and coins of the old national currencies were in certain cases legal tender from 1 January 1999 to 28 February 2002. Legally, these notes and coins were considered non-decimal subdivisions of the euro. [ref. needed] The Swiss franc is legal tender in Switzerland. Any payment of up to 100 Swiss coins is legal tender; Banknotes are legal tender for any amount.  The Australian dollar, consisting of banknotes and coins, is legal tender in Australia. Australian banknotes are legal tender under the Reserve Bank Act 1959, p.36(1), with no limit on the amount.
The Currency Act 1965 also provides that Australian coins intended for general circulation are also legal tender, but only in the following amounts: Sometimes, monetary issues such as commemorative coins or remittance slips may be issued that are not intended for public circulation but are nonetheless legal tender. An example of such a currency is the Maundy currency. Some currency issuers, notably Scottish banks, issue special commemorative notes for normal circulation (although no Scottish or Northern Irish notes are legal tender in the United Kingdom). In addition, some standard coins are minted on higher-value dies as “non-circulating” versions of the coin, which collectors can purchase for an additional fee. These documents are nevertheless legal tender. Some countries issue precious metal coins on which a monetary value is indicated well below the value of the metal containing the coin: these coins are called “non-circulating legal tender” or “NCLT”. Council Regulation (EC) No 974/98 limits the number of coins that may be offered for payment to fifty.  The governments issuing the coins must establish the euro as the sole legal tender. Due to the different legal meanings of the term `legal tender` in different Member States and the possibility for contract law to prevail over legal tender, it is possible for traders to refuse to accept euro banknotes and coins in certain euro area countries (the Netherlands, Germany, Finland and Ireland).  National legislation may also impose restrictions on the maximum amounts that can be paid per coin or banknote.
Banknotes are not legal tender in Scotland.  Scottish banknotes are legal tender but are not legal tender anywhere in the United Kingdom.  The right of a merchant to refuse to do business with a person in many jurisdictions means that a potential buyer cannot force a purchase solely by presenting legal tender, as legal tender must only be accepted for debts already incurred. The sixth series of Swiss banknotes from 1976, recalled by the SNB in 2000, is no longer legal tender, but can be exchanged for regular banknotes until April 2020. Maundy currency is legal tender but may not be accepted by retailers and is worth much more than its face value due to its rare value and silver content. The United States issues several denominations, with the most common beings: 1¢, 5¢, 10¢, 25¢, 50¢ and $1. It also issues collector`s and commemorative coins for sale. These coins honor a person, place, or event. According to the Economic and Monetary Union of the Republic of Ireland Act 1998, which replaced the legal tender provisions that had been incorporated into Irish law in previous UK laws, “no person, other than the Central Bank of Ireland and such persons as may be designated by regulation by the Minister, shall be obliged to accept more than 50 euro or cent coins in a single transaction”.
In 1933, the Coinage Act allowed certain New Zealand coins and stripped British coins of legal tender.