What happens to Charles's passport?
Queen Elizabeth II (of the UK and other assorted Commonwealth realms) somewhat famously did not have a passport. (The theory being that passports are technically issued in the Monarch's name, so it would have been superfluous/nonsensical for her to issue one to herself.) However, all other members of the royal family are issued passports.
What happened to Charles's passport once he became King?
I fully realize that as King, Charles does not need a passport, and in practice he would not use one for any future international trips. What I'm asking about instead is the formal validity of his existing passport. Is the passport that was issued to Charles, Prince of Wales, still technically a valid document, or was it officially voided upon his ascension?
I'd also be interested in any other documents (e.g. driver's license) which the Monarch is not issued, but which the Prince of Wales would have been. Also, while I've tagged this as UK, I'm asking generally about any/all of the Commonwealth realms, especially to the extent the answer is different.