With millions of Americans voting by mail this year, the hunt for a stamp has replaced the "I Voted" sticker as a marker of the election.
But if you forget to put one on—or you don't get the right amount of postage—your mail carrier will still deliver it.
The U.S. Postal Service's official policy is to deliver all absentee and mail-in ballots, regardless of whether they have proper postage, according to spokeswoman Sue Brennan. If there's no stamp or not enough postage, the Postal Service charges the local board of elections instead.
"Technically, sending mail requires postage," Brennan told TIME in an email. "Voters should affix a stamp to their ballot. But, if they do not, the Postal Service will still deliver it and charge the postage to the appropriate office."
That doesn't apply if you're sending your ballot from overseas or a non-Postal Service facility, where you'll definitely need to attach the correct postage, however.
Twenty-seven states and the District of Columbia allow no-excuse absentee ballots, while 20 states allow voters to request them if they have a reason. Washington, Oregon and Colorado vote entirely by mail. In 2012, more than 6 million domestic voters mailed in their ballots, while another 23 million sent them from overseas, including military bases. That number is expected to increase this year.
In some counties, the ballots are long enough that the postage is more than just the usual 47 cents. In Washington state's Snohomish County, voters are supposed to pay 68 cents for an oversize envelope or else return the ballot to a drop-off point for free delivery.
In New Jersey, some mail-in ballots were returned this month because of a design flaw in the envelopes that caused problems with the machines that read addresses, but Postal Service policy is that ballots "must never be returned" because of a lack of a stamp.
Some voters are also finding that putting just the right stamp on their ballot is one more way to express their feelings on this year's election.
Harry Potter stamps have proven popular, especially for people who want to say "I'm With Her...mione."
Gay rights pioneer Harvey Milk was another pick.
One voter made a comment about Islam.
Actress Yvette Nicole Brown made a statement about Donald Trump's controversial Access Hollywood video.
While others hoped to be saved from the election year.