AN INCREDIBLY special £20 bank note has sold for staggering amount of money because of a series of numbers people usually ignore.
Most pay little or no attention to the money in their pocket or wallet, but you could be totally unaware you're carrying around a tidy sum.
The value of notes can rise or fall depending on its serial number.
For collectors, though, notes with a low serial number are particularly sought after due to the huge amounts of money they can be sold for.
It comes as a £20 note, carefully kept in a glass frame, sold for a remarkable £9,400 at auction.
Issued by the Bank of England in 1999, the note has "the lowest possible circulation serial number" available in its series at "AA01 000005".
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It is now tradition for the Bank to withhold the first notes it prints, each with low symbolic serial numbers.
Rare notes are usually then attributed to "dignitaries, royalty and institutions that usually receive or were involved in the development of the new issue".
The King received the very first note, usually with the serial number "000001".
Notes with the serial number "AA01 001945" are handed to the Churchill War Rooms to mark the end of World War Two.
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Other notes of significance also include the "AA01 001817" given to Winchester Cathedral to celebrate the year Jane Austen was buried there.
The description of the lot, sold by London Coins, adds: "A number of first run circulation serial numbers, the Bank of England is known to donate in Charity Auctions for various causes and many of these notes are very sought after by collectors and usually realise high figures."
On the £20 note, it adds: "In regard to this note the serial numbers prior to this one were reportedly donated as follows to H.M. the Queen, the Prime Minister, the Bank of England Governor and the Chancellor."
Pictures show the note in pristine condition, having been placed carefully inside a glass frame.
The note is held in place with small holders, with a small gap for each corner to be inserted in.
Is your small change worth a fortune?
IF you think that you might have a rare coin then you might be able to make a real mint.
The most valuable coins usually have a low mintage or an error.
These are often deemed the most valuable by collectors.
You should check how much the coin is selling for on eBay.
Search the full name of the coin, select the "sold" listing and then toggle the search to "highest value".
It will give you an idea of the amount of money that the coin is going for.
You can either choose to sell the coin on eBay or through a specialist such as ChangeChecker.org.
If you choose the auction website then remember to set a minimum price that is higher or at the very least equal to the face value of the coin.
Even if your coin "sells" on eBay for a high price there’s no guarantee that the buyer will cough up.
It its terms and conditions, the auction website states that bidders enter a "legally binding contract to purchase an item", but there’s no way to enforce this rule in reality.
The most eBay can do is add a note to their account for the unpaid item or remove their ability to bid and buy.