When will we know the election results? What you need to know about vote counting.

In 2020, the Associated Press and other news media determined that Joe Biden had won the presidency four days after the election. The swing states that took the longest then could be slow again this year: Pennsylvania, Arizona and Nevada. If the race is close, other states could join the list.

In addition to legal restrictions on when officials can count ballots, long lines at polling places at the end of the day can also delay counting, because voters in line at closing time are still allowed to vote.

And then there are the ballots of overseas voters and military personnel, which sometimes arrive after Election Day, along with provisional ballots of voters whose eligibility is in question. In very close elections, the outcome is unclear until the last ballots are counted.

Here’s a look at the seven battlegrounds and when results can be expected.

Pennsylvania

In 2020, the Associated Press called the state for Biden on the Saturday after Election Day. Election officials expect the count to take several days again this year.

Unlike many states, officials there are not allowed to begin processing absentee ballots until 7 a.m. on Election Day. The process is laborious. Employees must check that voters have provided all necessary information, then remove the ballots from the envelopes, unfold them, ensure they are not damaged, and enter them into the voting tabulations.

Pennsylvania has arcane rules that can lead to problems with ballots. Absentee ballots must be placed in a confidentiality envelope, which is then placed in a mailing envelope. The envelopes must be properly dated. If mistakes were made, ballots may not be counted.

Arizona

Four years ago, Fox News and the Associated Press called Arizona for Biden on election night, a move others called premature. Most networks waited days to determine whether Biden would win the state. This time, unofficial results could again take so long.

Arizona allows election officials to process early ballots as soon as they receive them, but many voters wait until Election Day to drop them off.

There are concerns that it could take even longer to count votes in Arizona this year because voting is taking an unusually long time. In Maricopa County, the state’s most populous county, races and voting questions span two pages instead of one — meaning voters and officials will have to enter twice as many pieces of paper into vote-counting machines this year. This increases the chance of paper jams that delay the counting of votes.

Nevada

In 2020, the Associated Press called Nevada for Biden the Saturday after Election Day.

Voting in Nevada is largely done by mail, and Secretary of State Cisco Aguilar, a Democrat, has advised counties to start counting ballots as soon as polls open on Election Day, rather than after they close as in the past.

On Election Day, after the last voter has voted, the Secretary of State will give counties the green light to release the totals of all in-person ballots and all ballots received before that day. What remains are in-person ballots on Election Day and mail-in votes that arrive that day or later. Election Day totals will start trickling out Tuesday evening, but are unlikely to be fully reported until later in the week.

Most states require ballots to be returned before Election Day, but Nevada counts unpostmarked ballots that arrive up to three days after Election Day and ballots postmarked up to four days after Election Day. This creates uncertainty about when the results will be known, especially in a close election. The second largest day for receiving mail-in ballots in Nevada is typically the day after the election.

Georgia

Networks called Georgia for Biden on Friday after the 2020 election. Election officials expect the count to move faster this year.

Election officials can process absentee ballots as they arrive and begin counting them at 7 a.m. on Election Day.

An hour after the polls close on Election Day — scheduled for 7 p.m. Eastern time — state election officials plan to release the counts of all processed mail ballots and early ballots. Early voting has been extremely popular this year and more than half of registered voters have already voted. Officials estimate that most Election Day figures will be released before midnight on Tuesday. They will also post the total number of ballots cast that day so the public knows how many ballots remain to be counted.

A few laggards will take longer, including likely Fulton County, the state’s largest jurisdiction, which is operating a new counting facility this year.

Michigan

Michigan was called for Biden the day after Election Day. This year, Secretary of State Jocelyn Benson, a Democrat, said she expects unofficial results for the state by the end of the day on Wednesday.

Large and medium-sized communities started processing their ballots last week this year; communities with fewer than 5,000 residents can process them on Monday. All jurisdictions count votes on Election Day.

In 2022, Michigan passed a measure allowing early in-person voting. Those who vote that way enter their ballots into the tabulation just as they would on Election Day. That means less work for clerks on Election Day and should help speed up the count.

Wisconsin

In 2020, the count in Wisconsin was completed early in the morning, the day after Election Day, and that afternoon the Associated Press called the state for Biden.

Election officials cannot count mail-in and in-person early ballots until Election Day, which could lead to delays in counting.

Milwaukee, a Democratic bastion and the largest city in the state, is expected to be one of the last cities in the state to report full results as it takes time to count ballots at the central counting facility and mail ballots by mail. to send mail. Milwaukee’s elections director expects to have complete unofficial results sometime after midnight. A few other jurisdictions in the state could report their results next.

North Carolina

The state has historically reported most results relatively quickly and could provide early clues about how Trump and Harris will fare nationally.

The counting process is faster in North Carolina because election officials can remove ballots from their envelopes and enter them into tabulators weeks before Election Day. They count those results on Election Day, but can’t announce the results until the polls close at 7:30 PM Eastern Time.

Election officials will first report the totals for mail-in ballots and later the totals for those who voted early in person or on Election Day.

Because of the damage from Hurricane Helene, some counties will have to send their results to election offices instead of handing over computer memory sticks. This could delay the reporting of results in some provinces.