The holy grail of change collecting: The unique 20p coin that sells for nearly 350 times its face value

Dubbed "the holy grail of change collecting" by The Britannia Coin Company of Royal Wootton Bassett, this unique coin is the result of a printing error in 2008.

A County Durham seller has recently sold their undated 20p coin for £69.99 – nearly 350 times its face value.

The coin, which was struck without a date in 2008, is said to be the "holy grail of change collecting" by The Britannia Coin Company of Royal Wootton Bassett.

The error occurred when a batch of the coins was struck without a date at the Royal Mint in November 2008.

Out of the 136 million 20p coins produced during 2008, around 250,000 were struck without a date.

The mistake happened because an older obverse design ('heads' side) was paired with a new royal shield reverse ('tails' side), leaving the date completely missing.

Coin collecting has become increasingly popular in recent years, with many people searching through their change in the hopes of finding a rare coin which could be worth a small fortune.

The undated 20p coin is one of the most sought-after coins by collectors at the moment, and one lucky seller in County Durham has recently sold theirs for £69.99 on eBay.

The coin, which is described as being in "good circulated condition", sold for 350 times its face value on the online auction site.

Meanwhile, The Britannia Coin Company lists similar coins on their website for as much as £90.

The coin-selling website explains: "These coins have been circulated, so they will show the signs of wear typical of change that has been in wallets and cash registers. The only difference is this unusual error."

The undated 20p coins were struck at the Royal Mint in November 2008 and are said to be worth up to £90 to collectors (Image: The Britannia Coin Company)

Top Tips to Check for the Rare 20p Coin in County Durham:

The 20p coin was first introduced in 1982 to replace the 2 shilling piece, and is now the seventh most valuable circulating coin in the UK.

The coin is made from cupronickel and features the profile of Queen Elizabeth II on the obverse side.

The reverse side of the coin usually features the year of production, along with the design of a heraldic rose, leek, thistle and shamrock.

However, on the undated 20p coin, the year of production is missing, making it a valuable error coin.

To check if you have an undated 20p coin, simply have a look at the reverse side of the coin.

If the year of production is missing, then you could be in possession of a valuable error coin.

It is worth noting that the coins will show signs of wear and tear, as they have been circulated.

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.

Royal Mint top 10 most valuable 50p coins

Here is a list of the top 10 most valuable coins, when they were made and how many were minted:

Queen Mother and Red Arrows feature on new Royal Mint coin designs for 2025

Five new coin designs for 2025, including those depicting the Red Arrows and and Queen Elizabeth, the Queen Mother, have been unveiled by the Royal Mint.

It is a first glimpse for collectors to see some designs which will appear on commemorative coins in 2025.

The Royal Mint’s 2025 annual set, which will be available next week, includes new designs for the 50p, £2 coin and £5 coin.

Two 50p coins have been designed to celebrate the 60th anniversary of the first Red Arrows display, and to