A new 12-sided £1 coin entered circulation on Tuesday, as it starts to edge out the old “round pound” after more than 30 years.

The new coin has been described as the most secure coin in the world and boasts high-tech features, including a hologram.

But consumers craving a snack or trying to park may face confusion when they attempt to pay at coin-operated machines, as some will not immediately accept the new coin.

They may find themselves rifling through their wallets for an old round pound.

Tesco trolleys across many of its stores will be unlocked as the supermarket giant performs upgrades so that they can accept the new coin.

A Tesco spokesman said last week that “fewer than 200” of its stores will be affected.

He said last week: “We will continue to have colleagues on hand to attend trolleys in our stores, so our customers aren’t affected by the changes.”

The old coin and the new coin will co-exist together for a period of around six months, until the round pound ceases to be legal tender on October 15.