Twitter and Facebook will hand over the digital keys to @POTUS, as well as other official social media accounts, to Joe Biden on Inauguration Day even as President Donald Trump continues to reject his election defeat.

The social media giants said the @POTUS handle and those for the White House, vice president and first lady will be transferred on Jan. 20. Twitter spokesman Nick Pacilio told Reuters this weekend that the company is making preparations just “as we did for the presidential transition in 2017,” and that it is doing so in consultation with the National Archives and Records. Twitter did not immediately respond to a request for comment from The Post.

Facebook expects a “seamless” transition of the relevant Facebook and Instagram accounts to the new administration, the company said in a statement emailed to The Post.

“In 2017, we worked with both the Obama Administration and incoming Trump Administration to make sure the transition of their Facebook and Instagram accounts was seamless on January 20th, and we expect to do same here.”

@POTUS is separate from the account from which Trump so prolifically tweets and that has come to define his presidency. His personal account, @realDonaldTrump, has been his primary megaphone to air his grievances and opine on trade deals, national security, the election and other topics. He is one of Twitter’s most influential figures, with nearly 89 million followers. He has tweeted more than 58,000 times.

Trump’s tweets often come with real-world reverberations, particularly in the financial world. A Bank of America analysis from last September found that, since 2016, days where the President tweeted more than 35 times were associated with negative market returns. A Barron’s analysis, also from last September, calculated that the S&P 500 fell an average of 0.3 percent on days when Trump tweeted more than 20 times.

JP Morgan analysts created a “Volfefe index” – a mash-up of volatility and Trump’s 2017 “covfefe” incident – to track the relationship between the president’s tweets and Treasury yields. Earlier this year, the index signaled that volatility in the Treasury market linked to Trump’s tweets surpassed those linked to traditional sources of monetary and economic policy announcements, Bloomberg reported.

In recent weeks, Trump’s recent tirades over the election results and false claims of mass voter fraud have repeatedly been flagged by Twitter. In one tweet Sunday, the president claimed that “in certain swing states, there were more votes than people who voted, and in big numbers,” while also alleging “fake ballots” and “egregious conduct.” Fact-checkers have repeatedly investigated viral claims that vote counts exceeded registered voters in various locales, and found them all to be false. Twitter flagged Trump’s tweet as being “disputed.”

He’s also used the platform to call out members of his administration. Last week, Trump announced the firing of Christopher Krebs, who headed the Cybersecurity and Infrastructure Security Agency at the Department of Homeland Security and led successful efforts to help state and local election offices protect their systems and to rebut misinformation. He also announced the firing of Defense Secretary Mark Esper through a Nov. 9 tweet.