The filing with US Securities and Exchange Commission states that all previous members of the board are no longer directors after Musk’s takeover was “consummated” on Thursday.
This includes the ousted CEO Parag Agrawal and chairman Bret Taylor, it states, saying this is “in accordance with the terms of the merger agreement.”
This means Musk, the richest man in the world, is the “sole director of Twitter”.
According to reports, Musk is said to be considering sweeping job cuts at the social media giant.
The Washington Post reported that Musk plans to cut Twitter’s workforce by around a quarter of staff - approximately 2,000 people - in a round of layoffs.
Twitter has not commented on the report.
Other changes reportedly being considered by the entrepreneur are charging up to $20 (£17) for gaining a ‘blue tick’ on the site.
Musk tweeted that the verification process, marked by a blue tick, would be revamped, but did not give details. It is currently free.
According to technology site The Verge, the plan would mean making verification part of the Twitter Blue service, which is subscription-only, and putting up the price.
This would reportedly mean verified users having 90 days to subscribe or face losing their blue tick.
In a further sign of Musk’s control of the company, US media also report that the businessman has drafred in allies to help work on Twitter, including high-profile technology investor Jason Calacanis.