Queen Elizabeth reigned for 70 years, so her face is on pretty much everything. There are four and a half billion sterling banknotes featuring Her Majesty’s famous profile (worth £80 billion).
And on top of that, the Queen features on banknotes of other countries including Canada, New Zealand, and other parts of the Commonwealth.
Eventually, King Charles’s face will be on British currency, a process that is expected to take two full years at the very least.
Back in the day when changes between monarchs happened more often, it was “common” to have coins featuring different monarch’s faces in the rotation.
Coins with the Queen’s face on them will still be usable—as confirmed by the Royal Mint (which makes British coins) on its website.
While the Queen’s profile faces to the right on coins, Charles’s new coin faces to the left. The reason for it: it’s traditional for portraits to alter directions when a new monarch takes the throne.