It comes after legacy verified checkmarks were removed from the social app on Thursday as it continues to drive more people towards signing up for Twitter Blue.
“My Twitter account says I’ve subscribed to Twitter Blue. I haven’t,” tweeted King.
“My Twitter account says I’ve given a phone number. I haven’t.”
LeBron James previously said he would not be paying for Twitter Blue, though his blue tick remains.
Musk responded to King’s tweet and said “you’re welcome” after he confirmed on Twitter that he is personally paying the subscription for Twitter Blue on some verified accounts.
After reports some celebrities had been offered a complimentary Twitter Blue subscription on Musk’s behalf, the billionaire tweeted: “I’m paying for a few personally.”
American rap artist Ice T has called the verified checkmark discussion “a sad moment in society”.
“The fact that we’re even discussing blue checkmarks is a sad moment in society,” he tweeted.
Twitter Verified tweeted that legacy verified checkmarks would be removed from the site on April 20, with the main way of getting a blue tick being to sign up for Twitter Blue, with an £8 monthly fee for UK-based users.
The legacy checkmarks began disappearing towards the end of Thursday, with some of the biggest accounts losing their ticks including footballer Cristiano Ronaldo, cricketer Virat Kohli and former US president Donald Trump, as well as the official Twitter page for the pope.
In response to the blue tick removals, Musk posted a YouTube link to the song Blue (Da Ba Dee) by Eiffel 65 tweeting “Great song”.
Some Twitter users have a grey tick next to their accounts, which highlights that it is verified because “it is a government or multilateral organisation account”.
Users on Twitter with grey ticks include Rishi Sunak, Boris Johnson and Liz Truss.
Some users will have a gold tick to indicate that “it’s an official organisation on Twitter”, though some media outlets have had this removed from its account.
BBC News, CNN, NBC News and Fox News are among the affected outlets that no longer have a gold checkmark.
It comes as some companies have quit the platform over concerns that Twitter has undermined their credibility.
The Canadian Broadcasting Corporation (CBC) said it will be “pausing activities on Twitter”.
“Our journalism is impartial and independent. To suggest otherwise is untrue. That is why we are pausing our activities on Twitter,” it tweeted on Monday.
The move comes after Musk undermined CBC’s claims that it is “publicly funded through a parliamentary appropriation” and temporarily changed its bio to say “69% Government-funded Media”, though this has since been removed.
National Public Radio (NPR) also confirmed it will “no longer be active” on the social media site after it was labelled “state-affiliated media” and later changed to “government-funded media”.
“NPR’s organisational accounts will no longer be active on Twitter because the platform is taking actions that undermine our credibility by falsely implying that we are not editorially independent,” NPR said in a statement.
US publication the New York Times, which has 55 million followers on Twitter, has had its blue checkmark removed after it said it would not pay to remain verified.