In the United States, postal voting (commonly referred to as mail-in voting, vote-by-mail or vote from home) is a process in which a ballot is mailed to the home of a registered voter, who fills it out and returns it via postal mail or by dropping it off in-person at a voting center or into a secure drop box. Deadlines are set under state law, with some states requiring ballots be received by election day and others allowing ballots to be received after election day so long as they are postmarked by election day. Vote-by-mail is available in both Republican and Democratic states, with research showing that the availability of postal voting increases voter turnout. Five states—Colorado, Hawaii, Oregon, Utah and Washington—hold elections almost entirely by mail.