Nearly 16,000 mail ballots were rejected in Pennsylvania in April. That could be a larger number in November.

Voting rights groups are preparing voter education campaigns and encouraging local officials to minimize the number of ballots rejected in November after thousands of mail ballots couldn’t be counted last month.

The ballots are rejected for a variety of reasons — some are improperly filled out, others don’t make it to an election office before polls closed at 8 p.m. on Election Day.

Nearly 16,000 ballots fell into that category during the April primary. The number represented an improvement on previous years, something state officials attributed to a redesigned mail ballot. But it is still a significant number of votes that could determine the outcome of down ballot races in a higher-turnout general election while sowing distrust in the high-stakes presidential election.

While litigation remains pending on the state’s mail voting law, voting rights groups are calling for all 67 Pennsylvania counties to implement a “notice and cure” policy that gives voters a chance to fix their ballot before the election.

“Without clarity in the election code and without comprehensive notice and cure programs we’re going to continue to see bad faith actors in Pennsylvania use and exploit the issues on mail in ballots to breed voter distrust and to breed unnecessary litigation,” said Deborah Hinchey, Pennsylvania special projects director for All Voting is Local.

The 15,928 rejected ballots represents a small portion of the voters in Pennsylvania, even in a low-turnout election like April’s primary. But a similar proportion of rejected ballots in November could have a major impact when all eyes will be on Pennsylvania, as the state plays a key role in deciding the presidential race and which party controls the U.S. Senate.

Of the rejected ballots in April, 8,010 were rejected because they arrived at an election office after 8 p.m. on election day either because the voter or U.S. Postal Service returned it late. The other 7,918 were rejected because of issues with the date, signature, or privacy envelope.

According to data provided by the Pennsylvania Department of State, roughly 2.2% of mail ballots were rejected last month compared to 2.8% in the 2023 primary. State officials attribute the improvement to changes in the design of mail ballots.

“Ever vote is precious, every single one of them,” said Al Schmidt, Pennsylvania’s secretary of state. “We’re very happy that the data has shown that the redesign has been successful in reducing the number of ballots rejected as a result of voter error.”

The counting of undated ballots or those with incorrect dates has long been a subject of contention in Pennsylvania elections.

Just before the primary, in March, the U.S. Court of Appeals for the Third Circuit overturned a lower court decision that would have required Pennsylvania counties to count mailed ballots even if they were undated or had an incorrect date. The suit, filed by the NAACP, the ACLU, and other voting rights groups, argued the ballots should be accepted because the state law requiring dates served no purpose in determining a voter’s eligibility. If a voter casts a mail ballot in an election, it must be filled out between the day the county sends the ballots and the day it is returned, even if the date is not recorded.

Last month, the Third Circuit denied an appeal from the civil rights groups. But Marian Schneider, senior policy counsel for voting rights at the ACLU of Pennsylvania, said the plaintiffs in the lawsuit plan to file a new motion for summary judgment before the end of the month.

The ACLU is also currently challenging a decision in Butler County not to count provisional ballots cast by voters who realized after submitting their mail ballot that they had not used the privacy envelope.

Further litigation is likely between now and November either to limit the ballots that are cast or to expand counties’ options for counting ballots.

Some counties have processes in place to help voters fix their ballots if an error is detected before it is counted.

For instance, the Chester County Voter Services Office contacts any voter that has a deficiency on their ballot so they have the opportunity to come into the election office in person and fix their ballot. County election workers are also stationed at every remote drop box able to ask voters if they properly completed their ballot.

But those processes are not required. Hinchey said All Voting is Local is pushing local officials to begin working with voters on this.

“The situation that Pennsylvania is in is that our county boards of elections have to be proactive to enfranchise voters and our state legislature has to be proactive to clarify our election our election code and if our countries don’t do that thousands and thousands of Pennsylvanians could be disenfranchised,” she said.

At minimum, Schneider said, counties need to load information about incomplete ballots into the state’s voter database so that voting rights groups and partisan advocates can alert voters that they need to fix their ballot.

“That increases the odds that these voters will hear that they made a mistake and they can do something about it,” she said.

But some counties have held off on these processes, in part due to the lack of clarity in the law.

Various organizations, including the County Commissioners Association of Pennsylvania, have pushed the Pennsylvania General Assembly to pass laws clarifying Pennsylvania’s mail voting law so the details are no longer left to the court.

“They’re looking at the law and they’re trying to do the best they can,” Lisa Schaefer, the group’s executive director, said of local election officials.