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

In 2020, the Associated Press and other news outlets determined that Joe Biden had won the presidency four days after the election. The swing states that lasted 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 mail-in ballots, long lines at polling stations at the end of the day can also slow the count, as voters in line at closing time are still allowed to vote.

And then there are the overseas and military voters’ ballots, which sometimes arrive after Election Day, along with the 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 battleground states and when results can be expected.

Pennsylvania

In 2020, the Associated Press called the state for Biden the Saturday after Election Day. Election officials expect the tally to last 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. Workers must check that voters have provided all the required information, then remove the ballots from their envelopes, open them, make sure they have not been damaged, and insert them into the voting tabulators.

Pennsylvania has arcane rules that can lead to ballot challenges. Absentee ballots must be placed in a secret envelope which is then placed in a mailing envelope. Envelopes must be properly dated. If there are mistakes, the ballots cannot be counted.

Arizona

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

Arizona allows election officials to process early ballots as soon as they are received, but many voters wait until Election Day to withdraw them.

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

Nevada

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

Voting in Nevada is mostly done by mail, and Secretary of State Cisco Aguilar, a Democrat, has advised counties to begin tabulating those ballots as soon as the polls open on Election Day, rather than after they close, as they have did it in the past.

On Election Day, after the last voter has voted, the Secretary of State will give counties the green light to release totals for all in-person ballots as well as all mail-in ballots that arrive before that day. What’s left will be in-person ballots on Election Day, as well as mail-in ballots that arrive that day or later. Election Day precinct totals will begin rolling in Tuesday night, but are unlikely to be fully reported until later in the week.

Most states require ballots to be returned by Election Day, but Nevada counts unstamped mail-in ballots up to three days after Election Day and postmarked ballots up to four days after Election Day. This creates uncertainty about when the results will be known, especially in close elections. The second busiest day for receiving mail-in ballots in Nevada is usually the day after the election.

Georgia

The networks called for Georgia for Biden on the Friday after the 2020 election. Election officials expect this year’s count to go faster.

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

One hour after polls close on Election Day — which is scheduled for 7 p.m. ET — state election officials plan to release counts of all mail-in ballots and early votes. Early voting has been extremely popular this year and more than half of registered voters have already cast their ballots. Officials estimate that most of the county’s Election Day counts will be released before midnight Tuesday. They will also publish the total number of ballots cast that day, which will inform the public how many ballots remain to be counted.

A few outliers will take longer, likely including Fulton County, the state’s largest jurisdiction, which is running a new counting unit 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 to have unofficial results for the state by late Wednesday at the latest.

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

In 2022, Michigan passed a measure allowing early in-person voting. Those who vote this way enter their ballots into the tabulators 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 the morning after Election Day, and the Associated Press called the state for Biden that afternoon.

Election officials cannot count early mail-in and in-person ballots until Election Day, which may result in counting delays.

Milwaukee, a Democratic stronghold and the state’s largest city, is expected to be one of the last cities in the state to report full results as it needs time to count and mail its early ballots at the central counting unit. Milwaukee’s director of elections expects to have complete unofficial results sometime after midnight. Several other jurisdictions in the state may report their results after that.

North Carolina

The state has in the past reported the most results relatively quickly and could provide early indications of how Trump and Harris will fare nationally.

The counting process moves faster in North Carolina because election officials can remove mail-in ballots from envelopes and tab them weeks before Election Day. They tally those results on Election Day, but can’t announce the results until after the polls close at 7:30 PM Eastern Time.

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

Because of damage from Hurricane Helene, some precincts will have to call in their results to election offices instead of having memory sticks delivered to them. This could slow the reporting of results in some counties.