Millions of Americans who normally vote in person on election day will turn to early voting or mail-in ballots this fall — but that only works if you understand your state's election rules, deadlines and how to ensure your vote is counted.

Driving the news: Axios is launching an interactive resource, built on research by RepresentUs, a nonpartisan election reform group, to help voters across the country to get the information they need.

• "This election year, voters need to take more time and effort to navigate the challenges of a pandemic," U.S. Elections Assistance Commissioner Donald Palmer tells Axios.
• It will be critical for voters to have updated information on their options "to make sure that this election is a true reflection of the will of the people," said Matt Strabone, senior counsel for RepresentUs.

Why it matters: The more early voting there is, the greater the impacts if there are problems with the U.S. Postal Service, ballot shortages, confusion, lawsuits or delays.

• North Carolina will be the first state to send out absentee ballots, on Sept. 4.
• Minnesota and South Dakota will be the first states to allow voters to cast ballots early in person, starting Sept. 18.
• Texas, Tennessee, South Carolina, Mississippi, Louisiana, Kentucky, Indiana and New York require an excuse to vote absentee — though New York is poised to change, and more may follow.
• 11 states require absentee ballots to be notarized, have a witness signature or be submitted with a copy of an ID. If not done properly, ballots could be tossed.
• 32 states require mailed-in ballots to be received by Election Day, rules that could present problems if postal service delays continue through November.
• Voters in Rhode Island have until October 13 to request absentee ballots — and Oct. 20 in New Mexico and Nevada — the earliest cut off dates for submitting absentee ballot applications.

The other side: California, Colorado, Hawaii, Nevada, Oregon, Utah, Vermont, Washington and D.C. are automatically sending voters mail-in ballots — not just applications, as even more states are doing.

• Montana also has told counties they can opt into universal vote-by-mail, which all of them did in the primaries.

Between the lines: Taking advantage of early voting options could help limit crowds and long lines on election day, and lessen the risk of coronavirus infections.

What's next: Some election rules could still change. The Brennan Center is tracking litigation in 32 states, dealing with mail voting, early voting, voter purges, polling places and other election issues.