The new 12-sided pound coin will go into circulation on 28 March, marking the biggest change to the coin in over three decades.
Retailers can accept both coins during the co-circulation period running from 28 March until 15 October.
During this time, The Royal Mint has advised businesses returning pound coins to banks to use separate bags for new and old coins.
From 16 October onwards, retailers will be under no obligation to accept the round pound coin from customers and should only distribute the new 12-sided pound.
David Gauke, chief secretary of the Treasury, said the new coin will present a “significant barrier” to counterfeiters, benefiting business.