New five pound notes: Which serial numbers are the most valuable?

If you have a £5 note, you may want to take a closer look at it before you spend it. With the right serial number, it could be worth far more than its face value. 

The Royal Mint released the polymer note, which features a portrait of Winston Churchill, on 13 September and a total of 440 million have been printed.

Within days, it was reported that currency collectors were paying inflated prices to get their hands on notes with low serial numbers in the belief they will be worth far more in the future.

Here's how to tell if your fiver is worth more.

Which serial numbers are valuable?

The best fivers are those from the first batch, with serial numbers that start with "AA01". The rest of the number should be low to guarantee a high price. 

Some £5 notes with a different AA prefix, for instance "AA02", have sold for as much as £20 on eBay. Some sellers are also describing their notes as "rare" because of printing errors, such as misprints or smudges.

How much are rare £5 notes selling for?

One of the first notes given to the public, featuring the serial number AA01 000017, sold for £4,150 at a charity auction organised by the Bank of England on 3 October. 

A more realistic price for a rare fiver might be around £200, says the Daily Mirror, but this is still around 40 times the note's face value. One collector sold a set of three sequentially numbered £5 notes with low serial numbers for £456, adds the paper.

What happened to the first note printed?

Serial number AA01 000001 was given to the Queen fresh off the press, says the Daily Telegraph. It is not known what she intends to do with her fiver, although as she supposedly never carries cash she is unlikely to spend it.

Are there any tips for selling a rare £5 note?

Jenny Keefe from MoneySavingExpert says some £5 notes have sold on eBay for mere pence – one note with a starting price of 99p sold for just £3.20. 

"If you're selling a rare plastic fiver, always start the auction at least at £5 – you'd be surprised how many have closed for less than that sum," she told The Sun.

"Add in eBay fees and the loss is even bigger. There are so many fivers up for grabs on eBay that I wouldn't set a reserve price, as it might put people off."

eBay has its own list of general tips for successful selling. To maximise profits, make sure you "create listings that are more informative and attractive to buyers", for example, giving your listing a descriptive and searchable name.

Meanwhile, journalist and memorabilia collector David Seideman says that persistence is key when it comes to turning a profit in online auctions. "If an item fails to sell once, twice, or even three times, simply relist it," he writes in Forbes. 

Optimising your posting time can also make a difference – Seideman recommends adding new items on weekday evenings, to catch those browsing between returning from work and going to bed, without the distractions of the weekend to pull them away from the computer screen.

How to spot a fake £5 note

Although the new bills are purported to be harder to replicate, reproductions may nonetheless slip by in these early days of circulation as many people do not have a genuine £5 note to compare them against.

Here is a list of ways the Bank of England suggests you try to see if your fiver is genuine:

• Check that the image of Elizabeth Tower is gold on the front of the note and silver on the reverse.
• Check that the foil patch below the see-through window displays the words "Five" and "Pounds" when you tilt the note at different angles.
• Check that the rounded green foil patch on the back of the note not only exists but also contains the word "BLENHEIM".
• Check that if looked at under an ultra-violet light, the number "5" appears on the front of the note coloured in a green and red diamond pattern.
• Check that the crown appears to be three-dimensional.
• Check that there is a see-through window on the note, and that it contains an image of the Queen, encircled by the phrase "£5 Bank of England" twice.

If you're still worried about whether a note is fake, the Bank of England has a free smartphone app you can download for use on iOS or Android devices to help.