The new £1 coin will enter circulation on Tuesday.
The 12-sided coin will eventually replace the old 'round pound' which has been used for more than 30 years.
The new £1 has been described as the most secure in the world and boasts high-tech features, including a hologram.
The two coins will co-exist together for around six months, until the round pound ceases to be legal tender on October 15.
The new coins, which resemble the old threepenny bit, have been churned out by the Royal Mint in Llantrisant, South Wales at a staggering rate of three million per day.
But if you do get a new coin this week you may not be able to buy a snack or use a trolley with it.
Many coin-operated machines have not been modified yet and Tesco trolleys will also be unlocked as the supermarket giant performs upgrades so that they can accept the new coin.
But the Automatic Vending Association (AVA) said all vending machines will be fully upgraded by the end of the transition period in the autumn.
The majority of parking machines will should be ready - but some older machines may not be able to be upgrade.
One pound coins were first launched on April 21 1983 to replace £1 notes.
The Royal Mint has produced more than two billion round pound coins since that time.
But it has been easy to counterfeit with one in every 30 £1 coins in people's change in recent years said to be fake.
The new coin will be "harder to counterfeit than ever before".
Why is it being introduced?
There have been concerns about the old round pound's vulnerability to sophisticated counterfeiters - around one in every 30 round pounds is a dud.
The new £1 coin boasts new security features.
What security features does the new £1 coin have?
The features include its 12-sided shape, its bi-metallic structure with a gold-coloured outer ring and a silver-coloured inner ring and an image that changes from a "£" symbol to the number "1" when seen from different angles.
It also has micro lettering and milled edges.
What other features does it have?
The coin's design reflects England, Scotland, Wales and Northern Ireland, with a rose, a thistle, a leek and a shamrock.
The fifth coin portrait of the Queen, designed by Royal Mint coin designer Jody Clark, is featured.
The coin is thinner and lighter than the old coin but its diameter is slightly larger.
What is happening to the old coin?
There is a period of just over six months when the old round pound will still be accepted as legal tender alongside the new coin.
People are being encouraged to return their coins before October 15.
They can bank them or spend them. Some of the new £1 coins will be made from melted-down round pounds.