Children applying to 14 popular schools will have to go through balloting in the third of seven phases - Phase 2A2 - in the annual Primary 1 registration exercise.
They include Ai Tong School, which has 29 pupils vying for nine places; Gongshang Primary, which has 33 children registering for 25 ; and Temasek Primary, with 45 children trying for 13 slots.
The Ministry of Education (MOE) said on its website last night that for one of the schools - Westwood Primary - which has 77 pupils applying for 71 vacancies, all children with Singapore citizenship had been admitted in this phase.
Balloting will be conducted for permanent resident (PR) children residing within 1km of the school.
For the other 13 schools, balloting will be conducted for Singapore citizen children who live between 1km and 2km, or more than 2km, from the school. The results will be out tomorrow.
Phase 2A2 is for children whose siblings or parents are alumni, whose parents are staff of the school, or who are currently in a MOE kindergarten located in the primary school.
In recent years, some schools have faced a squeeze because of a rule introduced in 2014 that requires all primary schools to set aside 40 places for children in the later stages: Phases 2B and 2C.
Phase 2B is the fourth phase in the exercise. It is for children whose parents are school volunteers, active community leaders or have ties to church or clan associations directly connected with the schools. Registration for Phase 2B starts on Thursday.
Phase 2C is considered the most competitive, as it sees the most number of schools needing a ballot, compared with earlier stages of the exercise. It is for children with no ties to the schools. Registration for Phase 2C starts on Aug 3.
MOE has also said it will be introducing a cap on the intake of PR children in primary schools from this year's exercise. This will be about 25 per cent to 30 per cent of a school's planned Primary 1 intake, and will only be applied in Phase 2C and 2C Supplementary in 10 schools. The measure is to "prevent any concentration of PR children in our primary schools, provide a more conducive environment to encourage interaction between Singapore citizen and PR children, and facilitate the integration of PR children into Singapore", it said.
It added that the vast majority of primary schools and PR children will not be affected by this change, as past patterns of PR admissions are "well below the cap of 25 per cent to 30 per cent".
Registration has been moved completely online this year in the light of safe-distancing rules.