Martin Jennings Portrait of King Charles III
On September 30th 2022, the new portrait of King Charles III for use on coins was unveiled to the public. The portrait is by British sculptor Martin Jennings, whose initials MJ appear under the truncation of the bust.
In the past, new portraits have been prepared following the death of the reigning monarch, but "The sculptor Martin Jennings produced the concept for the portrait, which was personally approved by Charles, a year ago" (https://www.thetimes.co.uk/article/king-charles-iii-head-gains-currency-royal-mint-portrait-7hh9tdpqg). It is reportedly not the first portrait prepared while Queen Elizabeth II was still alive, though it is unclear if the previous portraits were prepared by other artists, or how advanced their preparations were.
The new portrait was also modeled from photographs rather than from a live sitting (https://bbc.com/news/business-63073983) as a number of previous portraits were: even previous portraits prepared from photographs were generally finalised with a live sitting.
For previous British monarchs the production of a coin portrait was usually long after the death of the previous monarch: the prevalence of collectable coins today has no doubt forced a change of tradition so that production of both circulating and non-circulating coins can continue without an anachronistic portrait.