The Polynesian nation of Tonga issues coins for circulation in the seniti unit of currency; the seniti is the fractional unit of the main unit, the Tongan pa’anga. Although 1 and 2 pa’anga coins were used in the past, currently Tonga only uses coins in seniti for regular commerce. Collectors’ proofs and other special coins are minted in several face values of pa’anga and the larger hau unit. Before the decimal system of the pa’anga, there was a short-lived system using koulas and pounds but coins were never circulated widely.
Tongan monetary unit values
1962:
1 koula = 16 pounds
1967 – now:
1 hau = 100 pa’anga
1 pa’anga = 100 seniti
Denominations of Tongan coins
If you want to collect one of each type of Tongan denomination that has ever been issued, you will need one of each of these:
Koula coins: 1/4, 1/2, 1
Seniti coins: 1, 2, 5, 10, 20, 50
Pa’anga coins: 1, 2, 5, 10, 20, 25, 50, 75, 100
Hau coins: 1/4, 1/2, 1, 5
Aland Islands coins collecting guide: Daler and euros of Ahvenanmaa
The three denominations of koula coins were only issued in 1962, all as gold proofs (and one as a platinum proof also). One and two seniti coins are too low-value to be seen in regular circulation, generally, while every coin of 1 pa’anga or more is now meant for collectors.
Tonga has issued a number of interesting and groundbreaking coins in its history. Several silver and gold proofs can be found, and certain buyers will be interested in the platinum and palladium coins that Tonga has issued. There are also some unusual shapes — most famously, rectangular coins and scalloped coins, for example.
The designs on Tongan coins tend to be very simple, with lots of flat unused space surrounding a simple portrait (usually of the King) or other image, plus a simple legend written around the rim in English or in Tongan using the English alphabet.