It said not all machines will be ready from day one and it will continue to work with businesses to ensure a smooth transition.
The new £5 note paves the way for a new generation of security features, making it harder to counterfeit.
They include a see-through window featuring the Queen's portrait as well as Big Ben shown in gold foil on the front of the note and silver on the back.
Bank of England Governor Mark Carney said: "The new fiver commemorates one of the greatest statesmen of all time, Winston Churchill, who remarked that 'a nation that forgets its past has no future'.
New GBP £5 Note - In pictures
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"Banknotes are repositories of the United Kingdom's collective memory, and we will be reminded of Churchill's enormous contributions as he once again becomes part of our daily lives as the new fiver flows out into tills and pockets."
Mr Carney said of the new note: "The use of polymer means it can better withstand being repeatedly folded into wallets or scrunched up inside pockets and can also survive a spin in the washing machine.
"We expect polymer notes to last at least two and-a-half times longer than the current generation of fivers and therefore reduce future costs of production."
The next £10 and £20 notes will also be printed on polymer.
