Australian twenty-cent coin
Production
The Australian twenty-cent coin was first introduced with the transition to decimal currency on 14 February 1966. It replaced the florin, which had been worth two shillings under the old pounds, shillings and pence system, and the two coins share a close physical resemblance. Stuart Devlin's platypus reverse has remained the standard design on the twenty-cent piece for the entire life of the denomination, making it one of the most enduring images in Australian coinage.
While the reverse design has stayed constant, the obverse has evolved with the reigns and effigies of the monarch. As with the other decimal denominations, the 2016 issue carried a special commemorative obverse celebrating the 50th anniversary of decimal currency. On the twenty-cent coin this obverse, designed by Ian Rank-Broadley, featured a reduced effigy of Queen Elizabeth II accompanied by a reproduction of the Coat of Arms as it appeared on the pre-decimal sixpence, together with the added legend FIFTY YEARS. Coins bearing the Dan Thorne effigy of King Charles III followed in 2024.
Initial 1966 production was shared between two mints, with the Royal Mint in London striking 30.0 million coins and the Royal Australian Mint in Canberra striking a further 28.2 million. In 1981, demand for twenty-cent coins exceeded the Canberra mint's capacity, so production was also contracted to the Royal Canadian Mint (50.0 million) and the Royal Mint at Llantrisant, Wales (50.0 million). Apart from these two years, all circulation twenty-cent coins have been struck at the Royal Australian Mint.
Twenty-cent coins are legal tender for amounts not exceeding $5. No twenty-cent coins were produced for circulation in 1986, 1987, 1989 to 1993 or 2023, and the coins struck for 1983 and 1984 were never released, with most later resmelted by the Mint. In 2022, the production cost of a twenty-cent coin exceeded its face value for the first time.
| Value | Mass | Diameter | Edge | Composition |
|---|---|---|---|---|
| $0.20 AUD | 11.3 g | 28.65 mm | Milled | 75% copper 25% nickel |
| Obverse | Design | Designer | Design date | |
| File:Australian 20c AM Coin.jpg | Elizabeth II | Arnold Machin | 1966-1984 | |
| File:Australian 20c RM Coin.jpg | Elizabeth II | Raphael Maklouf | 1985-1998 | |
| File:Australian 20c IBR Coin.jpg | Elizabeth II | Ian Rank-Broadley | 1999-2015
2017-2019 | |
| File:Australian 20c IBR50 Coin.jpg | Elizabeth II and Reproduction of the sixpence Coat of Arms | Ian Rank-Broadley | 2016 | |
| File:Australian 20c JC Coin.jpg | Elizabeth II | Jody Clark | 2019-2023 | |
| File:Australian 20c JCM Coin.jpg | Elizabeth II
Special Memorial |
Jody Clark | 2023 | |
| File:Australian 20c DT Coin.jpg | Charles III | Dan Thorne | 2024-Present | |
| Reverse | Design | Designer | Design date | |
|
Platypus | Stuart Devlin | 1966-Present | |
Mintage Figures
The tables below list circulation strikes of the standard platypus design. Years in which only commemorative designs were issued (1995 and 2003), or in which no coins were struck, are omitted; see Commemorative Issues below for those designs.
| Mintage year | 1966 | 1966 | 1967 | 1968 | 1969 | 1970 | 1971 | 1972 | 1973 | 1974 | 1975 | 1976 | 1977 | 1978 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mintage (Mil) | 30.0 | 28.2 | 83.8 | 40.5 | 16.5 | 23.7 | 8.9 | 16.6 | 23.4 | 33.5 | 53.3 | 59.8 | 41.3 | 37.4 |
| Mint | RML | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM |
| Mintage year | 1979 | 1980 | 1981 | 1981 | 1981 | 1982 | 1983 | 1984 | 1985 | 1988 | 1994 | 1996 | 1997 | 1998 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mintage (Mil) | 22.3 | 84.4 | 65.5 | 50.0 | 50.0 | 76.6 | 55.14 | 27.84 | 2.7 | 0.2 | 14.3 | 20.6 | 16.7 | 28.8 |
| Mint | RAM | RAM | RAM | RCM | RMLL | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM |
| Mintage year | 1999 | 2000 | 2001 | 2002 | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | 2013 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mintage (Mil) | 64.2 | 35.6 | 82.0 | 27.2 | 72.1 | 58.6 | 102.3 | 42.7 | 132.9 | 43.6 | 59.9 | 15.1 | 34.6 | 43.9 |
| Mint | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM |
| Mintage year | 2014 | 2015 | 2016 | 2016 | 2017 | 2018 | 2019 | 2019 | 2020 | 2021 | 2022 | 2024 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mintage (Mil) | 55.91 | 24.4 | 34.4 | 4.51 | 29.8 | 22.2 | 26.62 | 2.03 | 33.5 | 38.4 | 72.94 | 9.886 |
| Mint | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM | RAM |
| RAM = Royal Australian Mint; RCM = Royal Canadian Mint; RML = Royal Mint, London; RMLL = Royal Mint, Llantrisant |
| 1 = 50th Anniversary, 2 = IRB, 3 = JC, 4 = Struck for circulation but never issued; most were resmelted |
| No coins were produced in 1986, 1987, 1989-1993 or 2023. No standard platypus coins were issued in 1995 or 2003 (commemorative designs only). |
Commemorative Issues
The twenty-cent coin was a relative latecomer to circulating commemoratives: the 1995 United Nations coin was the first commemorative twenty-cent issue released into circulation. Since then the denomination has carried a steady stream of special designs, with the 2001 Centenary of Federation series of nine student-designed coins (one for each state and territory plus Norfolk Island) being the largest single program.
| Year | Commemorating | Mintage (Mil) |
|---|---|---|
| 1995 | 50th Anniversary of the United Nations | 4.8 |
| 2001 | Centenary of Federation - student designs (nine coins) | 2.1-3.2 each |
| 2001 | Sir Donald Bradman (1908-2001) | 10.0 |
| 2003 | Australia's Volunteers | 7.6 |
| 2005 | 60th Anniversary of the end of World War II | 33.5 |
| 2010 | Centenary of the Australian Taxation Office | 11.6 |
| 2011 | Wedding of Prince William and Catherine Middleton | 10.1 |
| 2011 | Centenary of International Women's Day | 6.8 |
| 2011 | 10th Anniversary of the International Year of Volunteers (IYV +10) | 6.1 |
| 2013 | Centenary of Canberra | 6.2 |
| 2016 | 50th Anniversary of decimal currency (special obverse, standard reverse) | 4.5 |
Mint Marks
The 1966 twenty-cent coin was struck at two mints: the Royal Mint in London (30.0 million) and the Royal Australian Mint in Canberra (28.2 million). Unlike the 1966 five-cent and ten-cent coins, no single widely accepted diagnostic feature separates the two mints at a glance, although the famous wavy baseline variety (see Varieties and Errors below) is associated with the London production run. Collectors attributing individual 1966 coins should exercise care before assigning a mint.
The most interesting minting year for this denomination is 1981, when demand exceeded Canberra's capacity and coins were also struck at the Royal Canadian Mint and the Royal Mint, Llantrisant. The Canadian strikes are distinctive to attentive collectors and cash handlers: the top and bottom edges of the milling are rounded over rather than squared as on the Australian and London coins, and even well-worn examples retain unusually shiny fields. Some Canadian coins also show a shortened first toe on the platypus's right claw, a variety known to collectors as the "3 1/2 claw". No mint marks appear on any of the 1981 coins.
| RAM / RMLL (squared milling) | RCM (rounded milling) |
|---|---|
| File:MintMark20cram.jpg | File:MintMark20crcm.jpg |
| RAM and Llantrisant coins: squared milling edges and dulled fields with wear. | RCM coins: rounded milling edges and shiny fields even when worn. |
Varieties and Errors
1966 Wavy Baseline
The wavy baseline is the most celebrated variety of the decimal twenty-cent coin and one of Australia's rarest circulating decimal varieties. It is identified by a wave on the top of the bottom stroke of the "2" in "20" on the reverse. The variety occurs within the 30 million coins struck at the Royal Mint in London in 1966, and only a small number of dies carried the defect. Well-worn examples found in change are typically worth $100 or more, while high-grade examples have sold for several thousand dollars. The variety is easy to miss: the wave is small, and the coin must be examined closely under good light. Genuine examples should show the wave integral to the stroke of the 2, not added by damage or tampering.
| Normal baseline | Wavy baseline |
|---|---|
| File:196620cnormal.jpg | File:196620cwavy.jpg |
| Standard 1966 reverse: the bottom stroke of the 2 is straight. | Wavy baseline: a wave ripples through the bottom stroke of the 2. |
1999-2005 Obverse Variations
Several variations of the Rank-Broadley obverse have been identified by collectors. The 1999 issue is found with thicker lettering, while the 2000 to 2003 issues show lettering very slightly reduced in size. The 2004 coin appears in two forms: a "small head", with the portrait reduced all around and thicker lettering, which was issued into general circulation, and a "large head" identical to the 2000-2003 obverse, which was only available in mint packs and is rarely found in circulation. Non-commemorative issues from 2005 onwards reverted to the large head obverse, while the 2005 World War II commemorative carried an even larger head.
1981 "3 1/2 Claw"
A subset of the Canadian-struck 1981 coins shows a shortened first toe on the platypus's right claw, described by collectors as the "3 1/2 claw" variety. Combined with the distinctive rounded milling and lustrous fields of the Canadian strikes, this variety adds a further level of attribution for collectors of the 1981 issue.
