The move comes after Twitter began removing the legacy blue verified checkmarks from thousands of accounts as the social media site continues its push to drive more people towards signing up for its paid-for Twitter Blue status.
Prior to Musk's takeover of Twitter, in order to receive the Verified badge, an account had to meet three criteria: authentic, notable and active. Types of accounts that were eligible for the verification included government, news organisations, brands and content creators.
Twitter Verified tweeted that these legacy verified checkmarks would be removed from the site starting from 20 April, with the primary way of getting a blue tick now being to sign up for Twitter Blue, which carries a monthly fee.
Users who pay £9.60 a month, or £115.20 annually, receive the blue tick and can post longer tweets up to 10,000 characters. Other select features available only to subscribers include non-fungible token (NFT) profile pictures, making changes to published tweets and seeing around 50 per cent fewer ads.
Twitter claims that its premium service "elevates quality conversations".
Some of the biggest accounts losing their verified ticks include those of footballer Cristiano Ronaldo, cricketer Virat Kohli and former US President Donald Trump, as well as the official Twitter page for the Pope.
However, it has been noted that author Stephen King, basketball star LeBron James and actor William Shatner are among a lucky few whose blue ticks remain, despite some claiming that they had not paid for the Twitter Blue subscription.
"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 had previously stated that he would not be paying for Twitter Blue, although his blue tick also remains.
Musk responded to King's tweet and said "you're welcome", confirming on Twitter that he is personally paying the subscription for Twitter Blue for some verified accounts.
After reports emerged that 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". He tweeted: "The fact that we're even discussing blue checkmarks is a sad moment in society."
Some Twitter users now 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 their account.
BBC News, CNN, NBC News and Fox News are among the affected outlets that no longer have a gold checkmark.
The official account for the Prince and Princess of Wales, William and Kate, had also been left without a tick on Thursday afternoon.
It comes as some companies have quit the platform over concerns that Twitter has undermined their credibility. The Canadian Broadcasting Corporation (CBC) recently announced that it would be "pausing activities on Twitter".
It tweeted on Monday: "Our journalism is impartial and independent. To suggest otherwise is untrue. That is why we are pausing our activities on Twitter."
The move comes after Musk undermined CBC's claims that it is "publicly funded through a parliamentary appropriation" and temporarily changed its bio to read "69% Government-funded Media", although this has since been removed.
National Public Radio (NPR) also confirmed it will "no longer be active" on the social media site after it found itself labelled as "state-affiliated media" and later changed to "government-funded media".
In a statement, the respected US public radio service said: "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."
US publication the New York Times, which has 55 million followers on Twitter, has also had its blue checkmark removed after it said it would not pay to remain verified.
Comedian Ricky Gervais personally let his 15.1 million followers know that his blue tick had gone. "My blue tick has gone. I'm not sure if I'm really me or not," he tweeted, alongside a zoomed-in image of himself.
British comedian and presenter Richard Osman quote-tweeted the official post from Twitter Verified about the removal of the legacy verified checkmarks after losing his, writing: "Farewell blue tick, old friend. Don't forget, always set your feed to 'Following' rather than 'For You'. Then you'll keep seeing the people you actually follow and not people who've paid for attention."
The financial troubles at Twitter were underscored this week when Microsoft dropped Twitter from its advertising platform, in light of Twitter's exorbitantly high-priced new API.
Twitter's new Enterprise plans for API access have a starting cost of $42,000 (£34,000) per month. A number of major companies and users have already walked away from Twitter and the eye-watering cost of using its new API.
Microsoft's announcement also came the day after Musk appeared at a marketing and advertising conference in an attempt to woo brands back to the platform. Twitter has reportedly lost half of its biggest advertisers following Musk's takeover of the company.
Musk responded to Microsoft's announcement by threatening a lawsuit on Wednesday, claiming the software giant used his company's data to train its AI. "They trained illegally using Twitter data," Musk tweeted. "Lawsuit time."
