Voting for the 21st South Korean presidential election began simultaneously at 6 a.m. Korean time (2 p.m. PDT on June 2) across 14,295 polling stations nationwide.
The total number of eligible voters for this election is 44,391,871, of which 15,423,607 participated in early voting on May 29-30.

This by-election, held to fill a presidential vacancy, will run for 14 hours, ending at 8 p.m.
Unlike early voting, in-person voting on election day can only be done at the polling station designated for one’s registered address.
Polling station locations can be checked via the voting guide mailed to households, the “voter registry lookup system” at local district, city, or county offices, or the polling station finder service on the National Election Commission (NEC) website.
Voters must bring a resident registration card, passport, driver’s license, youth ID, or any government- or public agency-issued photo ID. Stored images of mobile IDs are not accepted.

The NEC clarified that if a voter mistakenly marks the ballot or damages it, a replacement ballot cannot be issued. Those who voted early are listed in the voter registry and cannot vote again on election day to prevent double voting.
Former Prime Minister Hwang Kyo-ahn, who withdrew his candidacy after ballots were printed, will not have a “withdrawn” label on the ballots distributed at polling stations; only a withdrawal notice will be posted. The NEC warns that votes cast for a withdrawn candidate will be deemed invalid, urging caution.
Encouraging voter participation and promotional activities are allowed on election day but come with restrictions.

Voters may take “certification photos” showing a hand gesture indicating a candidate’s number and post or share them on social media (SNS).
It’s also permissible to post or share messages encouraging voting with text alongside photos of specific candidates’ posters or campaign materials, or to express support, endorsement, or opposition to a party or candidate. However, all photography must occur outside polling stations.

Taking photos of ballots inside the voting booth is prohibited, as is encouraging voter participation within 100 meters of a polling station.
At 8 p.m., when voting ends, polling station ballot boxes will be sealed with special tape and locks. Poll workers and observers will then transport the boxes to counting centers under police escort.
Early voting and mail-in ballot boxes, stored at district, city, and county election commissions, will be moved to counting centers by NEC staff, accompanied by party-recommended election committee members, observers, and police.
Vote counting results will be updated in real time by polling district on the NEC website.
Considering the time needed to transport ballot boxes, the NEC expects counting to begin around 8:30-8:40 p.m. The likely winner is expected to emerge around midnight, when the count reaches 70-80%.

The final voter turnout and results are projected to be fully tallied by 6 a.m. on June 4.
Under the Public Official Election Act, in a presidential by-election, the new president’s term begins the moment the winner is determined.
Upon completion of the vote count, the NEC will prepare materials and convene a full committee meeting. The NEC chairperson will then approve the decision to confirm the president-elect, and the new president’s term will start immediately upon this decision.
The NEC anticipates holding this meeting between 7 a.m. and 9 a.m. on June 4.
In the 2017 19th presidential by-election, also held due to a vacancy, the NEC convened a full committee meeting at 8 a.m. on May 10, the day after the election, and officially confirmed then-Democratic Party candidate Moon Jae-in as the president-elect.

Yonhap News