5 mistakes that can disqualify your November mail ballot and how to avoid them

• More states and counties than ever are allowing Americans to vote from home with a paper ballot mailed to their houses this fall.
• But voting by mail can be more prone to human error than voting in person, leading to mail ballots being rejected at higher rates than in-person votes.
• Already this year, an NPR analysis found that over half a million mail ballots have been rejected for arriving too late, missing signatures, or other errors.
• Here are the five biggest mistakes to avoid when filling out your mail ballot this fall, according to election experts.

This fall, 46 states and the District of Columbia are offering all voters the option to vote from home because of the COVID-19 pandemic.

While voting by mail allows voters to safely fill out their ballots in the comfort of their homes and avoid long lines at polling place, it's often more prone to human error than voting in person, especially for those unfamiliar with the process, leading to mail ballots getting rejected at higher rates than in-person votes.

The US Election Assistance Commission found that domestically, 33 million, or 23.7% of voters, cast ballots by mail in the 2016 presidential election. More than 318,000 of those votes, accounting for about 1% of the mail ballots that arrived at election offices, ended up being rejected.

This year alone, over half a million mail-in primary ballots have been disqualified for late arrival or other errors, according to a recent NPR analysis.

With anywhere from 40 to 70% of Americans expected to vote from home in November, the share of ballots that are rejected could be much higher.

Here are five common mistakes that could get your mail-in ballot challenged, disqualified, or not counted at all.

1) Improperly filling out your ballot

When you get your mail ballot, be sure to fill it out on a flat dry surface (no nearby coffee mugs or wine glasses) and carefully follow the instructions that come with it.

Similar to the multiple-choice standardized Scantron tests you took in high school, ballot scanners can accept only certain colors of ink and ballots that are filled out properly. Ballots can't have stray marks or multiple choices filled in for the same office.

"You don't want to use red ink, marker, or anything that could be problematic. If your instructions say to use black or blue ink, use black or blue ink. If it says fill in the oval, fill in the oval. I think it's really critical for voters to follow the instructions more than anything," Amber McReynolds, the CEO of the National Vote at Home Institute and a former director of the Denver Elections Division in Colorado, told Insider.

Adrian Fontes, the top election official in Maricopa County, Arizona, told Insider that county canvassing boards often must resolve major errors with mail ballots.

"If you're voting in person, and your ballot doesn't go through the tabulator, almost all models of tabulators will kick it back out and say there's something wrong, either a double vote, overvote, or something like that," he said. "In a vote-by-mail system, you don't get that second-chance opportunity, so those ballots have to be adjudicated."

And in some states, including the key battleground state of Pennsylvania, voters are required to seal and return their ballots in both an inner secrecy envelope and an outer envelope.

2) Forgetting to sign your envelope

Every state requires a voter to sign an affidavit on the outside of the envelope containing their mail ballot affirming their identity and eligibility to vote, so make sure you sign in every place that requires a signature.

Monica Lewinsky recounted in a recent Twitter thread how she went to extreme lengths to vote from abroad in the 2016 presidential election, including covering the expensive costs of getting her absentee ballot sent to her in Australia via FedEx and back halfway across the world to New York, only to return home and discover her ballot was rejected because she forgot to sign the outer envelope.

"The most common reason for rejection is people forget to sign," Rick Barron, the elections director in Fulton County, Georgia, told Insider. "If they don't sign the application, or they don't sign the ballot that's sent, that's really the only reason why we end up rejecting them."

3) Using a different signature from what your state has on file

Thirty-one states now use signature verification to confirm the authenticity of voted ballots, according to the National Conference of State Legislatures. In this process, election officials cross-check the signature a voter used to sign their ballot envelope to see if it matches the voter's most recent signature on file with the elections office, the Department of Motor Vehicles, or another government agency.

Signature matching adds an extra layer of security to ensure the integrity of mail ballots, but it can also lead to a greater share of ballots being challenged or rejected.

Kathleen Unger, a voter-protection attorney and the founder and board chairwoman of the nonprofit VoteRiders, told Insider that signature-matching problems could particularly affect younger and first-time voters.

"I used to think that this issue applied especially to older voters and to some folks with disabilities," she said. "But I then had this aha discovery after the 2018 election and saw that in the Parkland area of Florida, there were an excessive number of ballots rejected among young people because of signature issues."

In Georgia, too, young voters, first-time voters, and Black voters were far more likely than others to have their ballots rejected for mismatched signatures or for being incorrectly completed in 2018, one study found.

"Young people use one signature when they register to vote, and then they go off to college, become very creative, and their signature changes," Unger said. "I'm not ready to fall on my sword over this, but I think it's possible that signature matching could be the hanging chad of 2020."

McReynolds said that if you're not sure which signature your elections office uses or think your signature may be outdated, you can update your signature on file with your local elections office by submitting a new paper voter-registration form or on your paper mail-ballot application.

"Consistency is really what the election officials are looking for," McReynolds said. "We used to have people taking their ballot more seriously than everything else, so they'd write out a really nice, beautiful signature, and yet their voter-registration form did not include that. So consistency really matters."

At least 21 of the states that use signature verification have an established "cure" process to give voters a chance to correct any discrepancies with their signatures in order for their ballot to be counted, newly including Kentucky and New Jersey.

Those states need to have some form of contact information on hand to let the voter know of the problem and give them the greatest chance of having their vote counted.

"In Arizona, we ask for a phone number on the outside of the envelope that is not part of the public record but is part of the affidavit voters sign. So if we have an issue with a signature, we can call the voters back as quickly as possible," Fontes of Maricopa County told Insider.

4) Not including required additional documentation

While most states will allow anyone to vote by mail in November, not all states' rules are created equal. Some states require voters to take additional steps, like having a signature from a witness, to authenticate their ballot.

Thirteen states require all or some voters to submit a copy of their photo ID with their absentee ballots, and most people in Oklahoma and Missouri who vote by mail must get their ballot envelopes notarized.

Alaska, Louisiana, Mississippi, North Carolina, South Carolina, and Wisconsin will require voters to include one witness signature on their ballot envelopes in November. And Alabama requires each voter to submit a photocopy of their photo ID and obtain two witness signatures or notarization.

"In Wisconsin, all voters are required to have a witness signature, but we see a lot of voters who think that the witness signature is only required if they needed assistance, so there's a bit of confusion over that, which we are working to do some education around," Claire Woodall-Vogg, the executive director of the Milwaukee Election Commission, told Insider.

If you need help navigating the voter-ID laws in your state, affording the cost of obtaining an ID, or making a photocopy to send in with your ballot or application, organizations like VoteRiders can help.

"Based on a Brennan Center study showing that 11% of voting-age Americans do not have a current government-issued photo ID, that translates into about 25 million eligible voters," Unger said. "There are many millions more who are so confused and intimidated by these complicated and onerous voter-ID laws that they won't vote, even though they have a valid ID."

5) Sending your ballot back too late

One of the most common reasons mail ballots are rejected is that they arrive too late or lack a postmark.

Out of the 40 states not sending voters a ballot in the mail in November, 31 allow voters to request their ballots by mail within seven days of the election. For years, experts have said these tight deadlines set voters up to fail by not allowing enough time for a ballot to be delivered each way per the US Postal Service's delivery standards.

Now those fears are compounded by new organizational changes at the Postal Service that are delaying timely mail delivery in some parts of the country.

This year, 26 states require ballots to be received by Election Day or the day before in order to count, while 24 states and the District of Columbia require ballots to be postmarked by Election Day or the day before. If you're in a state where a ballot must be received by Election Day, the Postal Service recommends that you put your ballot in the mail at least a week in advance.

Judges in four key swing states, Georgia, Pennsylvania, Wisconsin, and Michigan, have ruled to extend receipt deadlines for mail ballots, decisions that could prevent thousands from being rejected for late arrival.

A traditional postmark is a dated stamp on the envelope that cancels the postage and prevents it from being used more than once. Some states now use alternative digital methods to verify when a ballot entered the mail stream so it can be accepted if it lacks that postmark.

"What we recommend is not just acceptance of postmark but also acceptance of a digital scan of an Intelligent Mail barcode or what we've been considering to be an electronic postmark," McReynolds said. "With the use of Intelligent Mail barcodes and more advanced technology, you can get electronic data showing when the ballot was first scanned by the Postal Service."

Tammy Patrick, a senior adviser at the Democracy Fund and a longtime liaison between election officials and the Postal Service, recommends that voters who mail in their ballots near or on the day of their deadline go in-person to a post-office branch and have their ballot envelope postmarked by a clerk.

The vast majority of states also allow voters to drop off their ballot in person at their local elections offices before the polls close, and a growing number of jurisdictions offer secure ballot drop boxes that are maintained by elections offices and allow voters to safely drop off their ballots by hand without using the Postal Service at all.