Elon Musk has said Twitter will charge $8 (£7) monthly to Twitter users who want a blue tick by their name indicating a verified account.
As part of changes after a $44bn (£38bn) takeover of the social media site, Mr Musk said it was “essential to defeat spam/scam”.
A blue tick mark next to a username – normally for high-profile figures – is currently free.
The move could make it harder to identify reliable sources, say critics.
Mr Musk, the world’s richest person, added that paid users would have priority in replies and searches, and half as many advertisements.
“Power to the people! Blue for $8/month,” the billionaire said on Twitter, criticising the old method of blue tick verification as a “lords and peasants system”.
But Nu Wexler, former Twitter Head of Global Policy Communications, warned that introducing a fee for blue ticks could make it harder to spot disinformation.
“With disinformation as an issue that a lot of platforms are struggling with, verification is one of the ways that journalists, academic researchers and some users use to filter out disinformation or low quality information,” Mr Wexler told the BBC’s Today programme.
-BBC