When does the new US president take office?

Donald Trump declared a “magnificent victory for the American people” as he appeared to be on track to become the 47th President of the United States.

Mr Trump won Pennsylvania, putting him just four electoral votes shy of defeating Kamala Harris to retake the White House. A win in Alaska or any of the outstanding battleground states — Michigan, Wisconsin, Arizona or Nevada — would send the Republican former president back to the Oval Office.

Ms Harris, 60, would have been the first woman, black woman and person of South Asian descent to serve as president. She also would have been the first sitting vice president to win the White House in 36 years.

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Mr Trump, 78, would become the oldest president ever elected and the first defeated president in 132 years to win another term in the White House. He would also be the first person convicted of a felony to take over the Oval Office.

British Prime Minister Sir Keir Starmer said the UK-US special relationship will “continue to prosper” following Mr Trump’s “historic election victory”.

"As the closest of allies, we stand shoulder to shoulder in defence of our shared values of freedom, democracy and enterprise," he added.

Inauguration Day - an 11 week wait

But while the 2024 US presidential election took place on 5 November - the winner will not be sworn into office until Inauguration Day on 20 January, 2025 - an 11-week wait. In contrast, in the UK, the winner of the general election is inaugurated the next day.

The longer wait in the US can in part be explained by the complex inauguration process.

Certification

After the polls close on Election Day, votes are counted by poll workers in thousands of individual voting districts across the country.

These results are normally reported to statewide databases on election night, which is how the US learns who is projected to become president. But these results, although almost always reflecting a clear winner, are still considered unofficial and uncertified.

After Election Day, the individual states embark on the certification process - including examining ballots rejected by voting machines and handling any conflicts surrounding the counting of the votes.

Electoral College

Once any disputes are settled and results are counted, they are sent to the state government to be certified by the governor. US presidents are not elected by a majority population vote, like many countries, but by electors from the US Electoral College.

Voters in the US vote not for the president, but for the candidate's electors in each state. For example, in Missouri, the candidates vied for the state’s 10 electors.

It has been announced that Mr Trump won the majority of Missouri’s vote, so he wins all the state’s 10 electors. A candidate needs 270 electoral votes to win an election.

Once the governor certifies the results, these electors meet in mid-December to cast the state’s official electoral votes - and this is then sent to Congress.

Electoral College vote count

Congress meets on 6 January to count the electoral votes from the 50 US states - with the US Vice President presiding and announcing the winner. In 2021, Donald Trump falsely claimed the election in the previous year had been "stolen" from him, which riled up far-right supporters enough to storm the US Capitol on 6 January to try to stop the vote count.

Later that day, Joe Biden was announced as the rightful winner.

During the period between the election and the inauguration, the president-elect prepares to carry out the duties of the office of president, working with the outgoing president to ensure a smooth handover of responsibilities. The incoming president will also announce their cabinet, including their picks for Secretary of State and Attorney General.

Former four month wait

For more than 100 years, the US did not inaugurate its president until March - a four month wait for the official handing over of power. That changed in 1933 during the Great Depression economic crisis, when Inauguration Day moved from 4 March 4 to 20 January - with the ratification of the 20th amendment to the US Constitution.

This was done so incoming president Franklin D. Roosevelt could limit the damage caused by the depression with a leaderless government.

The long wait from election to inauguration - outlined in the US constitution - initially had a logistical rationale too. The US centre of Government used to be located in New York City and in the 18th century, it would take a long time for people from the original 13 states of the US to travel there for the inauguration.