The new 12-sided 1 pound coin will enter circulationon March 28, the British government said.
The round 1 pound will be legal tender alongsidethe new coin until Oct 15.
The public are being urged to use their current 1pound coins or bank them before they lose theirlegal tender status.
Featuring the four symbols of the UK - a rose, leek, thistle and shamrock, the new coin is thesame shape as the old three penny bit, which was withdrawn in 1971.
The new style was announced in the 2014 budget and has been billed by the Royal Mint as"the most secure coin in the world".
It uses two colors of metal, has 12 sides and includes the Royal Mint's anti-counterfeitingtechnology, adapted from banknotes and embedded in coins for the first time.