The rare coin, which has previously been sold for more than £500, is still believed to be in circulation and features an error.
The coin shows the face of the First World War Lord Kitchener who featured on the “Your Country Needs You” posters.
It was released by the Royal Mint in 2014 to commemorate 100 years since the start of WW1.
While a normal version of the coin will be worth no more than its face value of £2, a batch of the coins featured a rare error that boost their value for collectors.
On some of the coins the words “Two Pounds” are missing on the head side of the coin.
According to experts at Coin Hunter, 5,720,000 of these coins are still in circulation but it appears to be “very rare” to find one without a date.
It isn’t clear exactly how many of coins with an error remain in circulation but the first of its kind sold in March 2020 for £500.
Coin Hunter experts said on Facebook: “Check your coins that feature Lord Kitchener.
“If the heads side does not show ‘TWO POUNDS’ – you have an error that appears to be very rare.”
What makes a coin valuable?
The 50 pence piece has become the most valued and collected coin in the UK, with many collectable designs appearing on its heptagonal canvas.
Its 27.5mm diameter makes it the largest of any British coin, and allows space for decorative pictures. It has often been used to celebrate big events over the past 50 years of British history.
The rarest coins tend to be of the greatest value, with the mintage (number of coins with each design made) being the fundamental attraction for collectors.
Along with the design, other aspects of the coin which increase value are the condition of the coin and whether it has an error in its design.
The way in which it is sold can also determine the coin’s value – while some coin collectors will bid vast amounts of money on ebay or at auction, others opt for more robust valuations by selling via a coin dealer.