Local election officials tabulate votes, including any mail ballots received after Election Day in states that allow them. After local results are verified by local election officials, the governor or other state official certifies the statewide results. The governor then prepares official documents with the state's formalized election outcomes and state of electors.
Each state has its own timeline for certifying election results. Here are key dates in swing states:
Arizona
Election officials have until Nov. 23 to finalize local results. The secretary of state certifies statewide results on Nov. 30.
Pennsylvania
By Nov. 10, local election officials must provide unofficial vote tallies to the secretary of the commonwealth. Nov. 23 is the last day for local officials to submit certified election results.
If there's a difference of 0.5% or less between the winner and the loser, the secretary of the commonwealth must order a recount by Nov. 12. If at least three voters in each county allege errors or discrepancies in the count, a recount could also be triggered. Any recount must be completed by Nov. 24, and local election officials must submit certified recount results to the secretary of the commonwealth by Nov. 25.
Michigan
Local election officials must complete counting by Nov. 17 and send results to the secretary of state within 24 hours. Election officials meet Nov. 23 to certify election results. Any petitions for recount must be submitted by Nov. 25, or within 48 hours after the end of the certification meeting.
Wisconsin
County officials have until Nov. 17 to finalize local election tallies. Under Wisconsin law, an "aggrieved" candidate can request a recount if they received within 1% of the winner's vote total. The loser can file a petition for a recount no later than 5 p.m. on the first business day after the state election commission has received final results from all counties. The Trump campaign has called for a recount in Wisconsin, where NBC News has Biden projected to win.
The Trump campaign would also have to pay the state for the cost of conducting the recount. It could total in the millions of dollars.
The Wisconsin Elections Commission must certify statewide results by Dec. 1.
Georgia
Local election officials must certify county results and send tallies to the secretary of state by Nov. 13. The secretary of state has until Nov. 20 to certify statewide results. The losing candidate is allowed to request a recount in Georgia if they lost an election by less than 0.5% of the total votes. That request can only be made to the secretary of state within two business days after the election results are certified.
Georgia Secretary of State Brad Raffensperger said Friday a recount is expected in the state, as Biden currently holds a narrow lead.
North Carolina
Dec. 8 — Last day for states to resolve election disputes
States must certify election outcomes at least six days before the Electoral College meets — known as the "safe harbor" deadline — if they want to avoid Congress getting involved in resolving potential disputes. That means any court challenges to state election results must be settled
by Dec. 8, 2020.
If states certify election outcomes by this deadline, Congress must accept the results as valid.
Dec. 14 — Electors cast their ballots
Electors meet in their respective states to cast their ballots for president and vice president on the Monday after the second Wednesday in December.
In every state except Nebraska and Maine, electors vote on a "winner takes all" basis, meaning whichever candidate wins the state's presidential race receives all of the state's electoral votes.
Electors send certificates of their vote to various officials, including Vice President Mike Pence, serving as president of the Senate.
Dec. 23 — President of the Senate receives electoral vote certificates Pence must receive the formal electoral vote certificates no later than nine days after electors meet.
Jan. 6 — Congress counts electoral votes
Any objections to the electoral votes must be submitted in writing and signed by at least one House and one Senate member. If an objection arises, the two chambers consider the objection separately.
Jan. 2021 — Inauguration Day
The president-elect and vice president-elect are sworn into office and officially become the president and vice president of the United States on Inauguration Day.