Each state has its own rules for the account and the order in which they report results.
Early results based solely on postal voting can therefore give Biden an advantage that Trump can then catch up with.
Here are some key states to keep an eye on tonight:
Texas (38 electoral votes) closes polling stations at 02 Swedish time
.
The constituencies decide how the bill goes and in what order they are published, but many are expected to count the early votes first.
This year, early voting is greater than the total turnout in 2016.
Florida (29) closes its last polling station at 02 Swedish time.
Then the counting of the early votes has been going on for two weeks.
This could provide an early lead for Biden, who is then eaten up by Trump when those who voted on election day are counted.
Votes received after November 3 are invalid.
Pennsylvania (20) closes at 02.
No votes may be counted before election day.
Results may be delayed when postal votes that are stamped on 3 November but arrive no later than the 6th are counted as valid.
The deadline is based on a court decision that can be overturned after election day.
These votes are therefore counted separately so that they can be deleted.
Ohio (18) polling stations close at 01.30.
Early votes are reported first.
Postal votes received no later than 13 November are valid.
Ohio has until November 28 to report final results.
Michigan (16) closes polling stations at 03
and in most districts may not count early votes before election day.
Reporting may take until November 6, but no votes received after election day are valid.
North Carolina (15) reports early early votes after noon. 01.30
which can give Bilden a valid lead.
Results may be available at 7 Swedish time, but the state allows late postal votes to arrive by 12 November.
Arizona (11), like Florida this year, allows early counting
of postal votes.
The first results are expected from kl.
04. Arizona has not indicated when they assess that they have been counted.
Wisconsin (10) closes polling stations at 03. The
results may be delayed until Wednesday evening Swedish time, but it is likely that several districts will report advance votes first.