Twitter said: "The past few months have proven we can make that work. So if our employees are in a role and situation that enables them to work from home and they want to continue to do so forever, we will make that happen."
Twitter's blog went on to say that for those keen to return to Twitter's office the company "will be their warm and welcoming selves, with some additional precautions".
The decision came as the social media giant said its work-from-home measures during the lockdown had been a success.
The announcement has been described as "an era-defining moment" by one digital innovation expert.
The San Francisco-based company employs more than 4,000 people across its global offices.
It has allowed employees to work from home since March and doesn't expect to reopen its offices before September.
Earlier this month Google and Facebook said their staff can work from home until the end of the year.