All voters will receive poll cards by May 3
About 2.2 million voters from the 26 contested wards have begun receiving their poll cards.
The Elections Department said all eligible voters will receive their poll cards by May 3.
Votes can be cast on May 7 from 8am to 8pm and voters have to take along their IC, passport or their National Service identity cards with their poll cards to the polling stations.
The poll cards state the polling station where they can cast their votes and voters have to go to the station that is indicated on their poll card and nowhere else.
There will be 732 polling stations in schools, community clubs and HDB void decks.
According to SingPost, some 963,000 poll cards have so far been dropped into letter boxes.
Overseas polling stations have also started sending the poll cards by mail to registered voters.
Overseas voting has to be completed by May 7 at 8pm (Singapore time).
The ballot will be conducted between 8am and 8pm local time on May 6 in London, New York, Washington and San Francisco.
It will be conducted between 8am and 8pm (local time) on May 7 in Canberra, Tokyo, Beijing, Hong Kong and Shanghai.