The new 12-sided £1 coin comes into circulation on Tuesday with a hidden security feature that would stamp out fraud and counterfeiting.

British retailers are switching to the new pound coin but people might have problems paying it for parking or getting a train ticket.

Royal Mint, who creates the coins, said the new pound coin contains a material that can be detected when electronically scanned by coin-counting or payment machines. Other security features include a hologram-like image and micro-sized lettering inside the rims. Mint claims the new pound coin will be the most secure coin in the world. It will replace the old £1 coin wherein more than 2.5 percent - approximately 1 in 40 - of which were found to be fake. 

"It's been designed to be fit for the future, using security features that aim to safeguard our currency, and currencies around the world, for years to come," Adam Lawrence, chief executive of the Royal Mint said in a statement. The old coin will continue to be legal tender until October 15  after which it will be considered unacceptable for payments. The new pound coin has already been delivered to at least 33 banks and post offices around the UK. 

Large grocery chains and supermarkets are already accepting the new pound coin. Tesco and Sainsbury have upgraded their self-service checkout machines and shopping carts. London's Tube has spent £250,000 ($315,000) upgrading more than 1,000 ticket machines. 

Meanwhile, consumers might encounter problems when using the new pound coin to pay for parking or getting a train ticket. There are still 49 machines on the London Overground that need to be replaced before it can accept the new pound coin as per a spokesperson. The British Parking Association also said at least one in eight parking machines will encounter problems since some of the machines have not been upgraded yet to include the new pound coins. It has estimated £50 million ($63 million) in upgrading the machines.

Vending machines and photo booths may, likewise, encounter problems in payment as about 75,000 machines still need to be upgraded to accept the new pound coin, according to the Automatic Vending Association. "There is a possibility that the new £1 coin may encourage a move towards cashless payments, however there is evidence to suggest that significant numbers of users do not trust new technology such as phone apps," Kelvin Reynolds, the association's director of policy and public affairs said.

While big retailers have chosen to adapt quickly to the new pound coin, smaller stores are not particularly happy to sort the old coins as they want to focus on serving customers and not counting coins, according to Chris Noice, spokesperson for the Association of Convenience Stores. 

Supplies of the new pound coin have been delivered throughout the UK, including seven in Scotland, three in Wales and two in Northern Ireland. Lloyds Bank, the biggest branch network in the UK, said the new coin will be available to its customers on Wednesday.