Once a final tally of voters’ in-person, mail-in and provisional ballots has been concluded, all 50 governors prepare their state’s Certificate of Ascertainment, a document listing their electors for the competing candidates.
Each state completes that process at its own rate. This year, because of the pandemic, finalizing the electoral vote count will likely take a lot longer. Once completed, copies of the Certificate of Ascertainment are then submitted to the U.S. Archivist.
After the governor submits names to the Archivist, each state’s Electoral College electors meet in the state capital—D.C.‘s meet in D.C. —to formally cast their votes for president and vice president on the first Monday after the second Wednesday in December. This year, that’s Dec. 14, 2020.
In ways that vary state by state, each state’s electors then prepares six Certificates of Vote, which are sent by registered mail to the President of the U.S. Senate and the Archivist of the United States. The remaining four certificates are sent to state officials.
That fulfills the Electoral College’s duties until the next presidential election.