Step 6. Prevent late ballots with essential voter communication. Election officials should consider adding a voter notification about the marked return ballot deadline in with the ballot packet. Marked return ballot deadlines are determined by state and local laws. For domestic nonmilitary voters, the Postal Service recommends that voters mail their marked return ballots at least 1 week before the due date to account for any unforeseen events or weather issues. For APO/FPO the Military Postal Service Agency recommends that military personnel serving overseas follow the return-by-mail date for their location published at https://usps.com/electionmail/. Voters returning their ballots via a Postal Service retail location may ask window clerks to roundstamp/hand cancel the postage. The roundstamp contains the date that the mail is accepted at an USPS office.