Apparently they'll starting circulating new coins here with King Charles III on them from next year. As expected, current coins and notes with Elizabeth II on them will still be legal tender until they reach the end of their lifespans too.
No decision yet on whether King Charles will also replace Queen Elizabeth on the $5 note here as well, or if someone else will replace her instead.
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It is easy to go down into Hell;
Night and day, the gates of dark Death stand wide;
But to climb back again, to retrace one's steps to the upper air –
There's the rub, the task.
– Virgil, The Aeneid (Book VI)