Australian 1920 pennies were minted in both Melbourne and Sydney. On the reverse side underneath the word "PENNY", is a scroll.
Coins minted in Melbourne will have a small dot under the scroll, coins minted in Sydney will have a small dot above the scroll.
Some coins have no dot and could have been minted at either the Melbourne or Sydney Mints.
The "no dots" coins are classified as rare.
This means of determining the mint, only applies to 1920 pennies.
The Australian 1943 Penny was minted variously at the Melbourne Mint (no mintmark), Perth Mint (mintmark is a dot after the Y in PENNY "Y.") and Bombay Mint (mintmark is an "I" under King George's bust).
A 1943 steel penny with no mintmark can be worth $.35 - $1.50
An Australian 1942 Halfpenny minted in Melbourne, has no mintmark. An Australian 1942 Halfpenny minted in Perth has a dot (.) after the (Y) in PENNY (PENNY.). An Australian 1942 Halfpenny minted in Bombay has an (I) below the King's head.
An Australian Penny or Halfpenny with a "Y." (PENNY.) mintmark indicates that the coin was minted at the Perth Mint. An Australian Penny or Halfpenny with a "I" mintmark indicates that the coin was minted at either the Calcutta or Bombay Mints in India.
An Australian 1956 Penny looks almost exactly the same as any other Australian Penny minted from 1955 to 1964 inclusive. A 1956 Penny minted in Perth will have a mintmark (.) after the "Y" in PENNY (Y.). The Melbourne Penny has no mintmark. See the 1964 penny at the link below.
1956 Australian Pennies minted at the Melbourne Mint have no mintmark. 1956 Australian Pennies minted at the Perth Mint have a dot (.) after the Y in PENNY (PENNY.)
The "S" mintmark on a 1943 steel penny indicates that it was minted in San Francisco.
KG is not a mintmark, it is the initials of the designer of the (kangaroo) reverse of the Australian 1938 to 1964 Penny and Halfpenny coins, George Kruger Gray. 1940 and 1941 Pennies minted at the Perth mint have a dot between the K and the G (K.G) as the mintmark.
The 1944 Australian Penny was minted at one of two mints. Melbourne Mint (no mintmark - 2.45 million minted. Perth Mint (mintmark = Y.) - 27.83 million minted.
Any 1942, 1943 or 1944 Australian Threepence, will have the "S" (San Francisco) or "D" (Denver) mintmark on the reverse of the coin, on the right hand side, just below the fourth digit of the year. Any coins minted in Melbourne will have no mintmark.
There is no "MP" mintmark on any Australian Penny. A 1941 Australian Penny minted in Perth will have a "." after the "Y" in PENNY (Y.), or a "." between the KG (K.G) on the reverse. A 1941 Australian Penny minted in Melbourne will have no mint mark at all. The letters HP on the obverse below King Georges head are the initials of the designer, Thomas Humphrey Paget. The letters KG on the reverse above the kangaroos tail are the initials of the designer, George Kruger Gray.
The mintmark is a "S" or "D" they are the ones used on the 1943 Lincoln steel cents. Average value is 5 to 10 cents.