The British Britannia Series has been one of the most prominent gold bullion coins in the world since its debut in 1987. The 1 oz gold coin is the centerpiece of the collection and has been available each year since 1987.

The Royal Mint of England delivers new security features on the reverse field of 2021 Britannia 1 oz Gold Coins. The most impressive and visually brilliant are the surface animation elements throughout the background and the latent security feature. As you adjust the angle of viewing, the surface animation reflects the movement of the oceans waves and the latent security feature changes between an image of a trident and a padlock. The stripes on the Union Jack have new tincture lines and the design rim has a micro-text inscription of Decus Et Tutamen.

The obverse side of 2021 British Britannia 1 oz Gold Coins includes an effigy of Queen Elizabeth II. The fifth-generation effigy of the Queen, this bust is a right-profile image that shows the Queen at the age of 89 wearing the George IV State Diadem Crown. Jody Clark developed this image of the Queen for British coins in 2015. Inscriptions on this face of the coin include 100 Pounds, Elizabeth II, and D.G. Reg F.D. The background field has a guilloche design element, a visual field that appears similar to a braided rope.

On the reverse face of 2021 British Britannia Gold Coins is a depiction of Britannia. This powerful female figure is the official personification of Britain and the term Britannia itself has been in use for more than 2,000 years now. Britannia is shown with a Union Jack shield and a trident in her other hand. Inscriptions here include Britannia 2021 and 1 oz 999.9 Fine Gold. The background field includes a sun on the horizon with a guilloche-style element of sun rays emerging from the sun.