Like many other mints, the Royal Mint issues bullion coins in precious metals, having much higher intrinsic value than their face value. Most of these by tradition are measured in troy ounces of fractions thereof, but the mint also introduced metric coins measuring one kilogram of pure metal (they are actually fractionally heavier as a whole, to account for the small amount of other metal in the alloy).
The 1 kg silver coins are denominated as Five Hundred Pounds (£500), although their intrinsic (bullion) value is much higher than their face value. The coins vary in design depending on the occasion (they are "one-year" types usually issued in parallel with smaller denominations with the same reverse designs).
The coins are legal tender but are not intended for circulation. They are targeted at bullion investors or collectors who appreciate the special editions as pieces of art.
Britannia coins belong to an extensive range of British bullion coins issued by the Royal Mint in gold since 1987 and in silver since 1997. The range has a "definitive" Standing Britannia design issued every year as bullion (such as this coin), and a series of one-year types issued as collector proofs only.
The one kilogram of silver format was added to the Britannia range in 2023.
The Royal Mint says about the coin:
Cast as the female personification of Britain for millennia, Britannia has continually evolved through the ages to capture and match the spirit of a nation and its people. First appearing on the coins of the Roman emperor Hadrian in the second century, Britannia has been a constant presence on British coins since 1672. Today, this icon appears on our flagship Britannia bullion coin. Renowned for its beauty and strength, sculptor Philip Nathan created this globally recognisable incarnation of Britannia in 1987. He presented the "queen of the seas" with carefully chosen symbols of Britain’s identity - a shield for protection, an olive branch for peace and a trident for her maritime links. Only The Royal Mint is able to strike genuine Britannia coins featuring Philip Nathan’s award-winning design and this modern classic has been struck on bullion coins dated 2025. | 
Search for United Kingdom: Silver Kilo 2025 Britannia on eBay 
