Halfpenny, Coin Type from Australia - detailed information

The Australian halfpenny (or half penny) coin was the smallest circulating denomination of the Australian Pound; unlike the British pre-decimal Pound Sterling, the Australian Pound had no smaller denominations like the British farthings and fractional farthings.

The Australian halfpenny has the same dimensions and composition as the British pre-decimal halfpenny, from which it is derived (for a time, the coins circulated in parallel and were interchangeable in Australia - but not in the United Kingdom; the currencies were fixed at par). 1/2 penny was worth 1/24 of a shilling, or 1/480 of a pound.

The reverse of the first type of Australian halfpenny coins features text only. In 1939, a new design superseded it - featuring the iconic leaping kangaroo; the old type of coins remained in circulation.

The coins were struck by a number of different mints, with various mint marks:
- Royal Mint, 1911 - 1914, no mint mark; 1951, letters PL
- Birmingham Mint (ex Heaton and Sons), 1912 - 1915, letter H; 1951, letters PL (as subcontractor for the Royal Mint)
- Calcutta Mint, 1916 - 1918, letter I
- Sydney Mint, 1916 - 1926, no mint mark
- Melbourne Mint, 1923 - 1959, no mint mark
- Bombay Mint, 1942 - 1943, dots before and after the denomination: .HALF PENNY., plus letter I on the obverse
- Perth Mint, 1942 - 1964, dot after the denomination: HALF PENNY. or a high dot after AUSTRALIA, or no mint mark

The coin was first minted in 1911 and minting ceased in 1964, excluding 1937, 1956 - 1958 inclusive. Counting the known mintages of proofs, a total of 422,882,890 (422 million) coins of the denomination were minted during its existence.

They circulated until decimalisation and were withdrawn in 1966, when Australia switched to its current Australian Dollar currency. Unlike some of the larger denominations, they were not re-denominated into units of the new currency. However, the halfpenny coins were never formally demonetised and are still legal tender for 5⁄12¢.