You may spot the tenner in your wallet looks a little different from today.

A new polymer £10 banknote has entered circulation.

Just over a billion of the notes, which feature a picture of Jane Austen, have been printed and will start to show up in people's pockets soon.

The note joins the £5 polymer note featuring Winston Churchill that is already in circulation.

Here's what you need to know:

What's changed?

The polymer note will replace the old paper £10 notes in the same way that polymer £5 notes have already been introduced.

The note is slightly smaller than the paper one and is the first Bank of England banknote to feature raised dots in one corner - so that blind and partially-sighted users will be able to feel them.

The feature was developed with the help of the RNIB.

Why polymer?

Mark Carney, Governor of the Bank of England, has said using polymer makes the new £10 safer, stronger and cleaner.

The new banknotes are expected to last at least two-and-a-half times longer than the current paper £10 notes, around five years in total, and stay in better condition during day-to-day use.

Does it have any disadvantages?

Some people think so. The transition to polymer sparked controversy after the Bank confirmed that an "extremely small amount" of tallow, or animal fat, was used in the production of the notes.

Last month, the Bank confirmed the animal fat would continue to be used with the £10, saying the only viable alternative was palm oil, which itself raises questions about environmental sustainability and value for money.

Can I still spend my old paper notes?

Yes. The old paper notes featuring Charles Darwin will be phased out gradually as they are banked.

They will cease to be legal tender in spring 2018 but the exact date has not be announced. The Bank has promised to give at least three months notice before they can't be spent.

Why was Jane Austen chosen as the face of the tenner?

This year has marked 200 years since the death of Austen, who wrote a series of novels including Pride and Prejudice and Sense and Sensibility.

Mr Carney said: "The new £10 note celebrates Jane Austen's work.

"Austen's novels have a universal appeal and speak as powerfully today as they did when they were first published.

Will there be any more polymer notes?

Yes. A new £20 note featuring artist JMW Turner will follow in 2020.