In presidential transitions, the president-elect does not receive the actual nuclear code card until after the nuclear briefing, which usually occurs when "he meets with the outgoing president at the White House just before the actual inauguration ceremony. The code card is activated electronically right after the president-elect takes the oath at noon".
In the event the outgoing president is not present at the inauguration – as happened in 2021 when Donald Trump did not attend the inauguration of Joe Biden but stayed in Florida – one football is kept with him and remains active until 11:59:59 AM on inauguration day. After that point, the now-former president is denied access to the football, its codes are automatically deactivated, and the aide carrying the football returns to Washington DC. In the meantime, the incoming president receives one of the spare footballs at the pre-inauguration nuclear briefing, as well as a "biscuit" with codes that become active at 12:00:00 PM.
From Wikipedia:
In presidential transitions, the president-elect does not receive the actual nuclear code card until after the nuclear briefing, which usually occurs when "he meets with the outgoing president at the White House just before the actual inauguration ceremony. The code card is activated electronically right after the president-elect takes the oath at noon".
In the event the outgoing president is not present at the inauguration – as happened in 2021 when Donald Trump did not attend the inauguration of Joe Biden but stayed in Florida – one football is kept with him and remains active until 11:59:59 AM on inauguration day. After that point, the now-former president is denied access to the football, its codes are automatically deactivated, and the aide carrying the football returns to Washington DC. In the meantime, the incoming president receives one of the spare footballs at the pre-inauguration nuclear briefing, as well as a "biscuit" with codes that become active at 12:00:00 PM.