Overseas voting was held until May 24. As for customs gates, voters will be able to cast their ballots until domestic polling stations close at 5 p.m. local time (1400GMT) on Sunday.
Millions of voters went to the polls on May 14 to elect the country's president and members of its 600-seat parliament.
Erdoğan's People's Alliance won a majority against the opposition's six-party Nation alliance in parliament.