NPR – During big U.S. elections, hundreds of thousands of mail ballots are typically thrown out and left uncounted. In 2020, for instance, more than 560,000 ballots were rejected (that’s nearly 1% of the total).

Experts say ballot rejections are largely the result of relatively minor voter errors, often associated with security measures that are designed to verify a voter’s identity.

That’s why about half of states have a process in place to help voters fix their mail ballots if they do make a mistake. It’s known as ballot curing.