It is only the third of seven phases in the Primary 1 registration exercise, but children applying to study at two popular schools may already need to go through a ballot.

When registration for Phase 2A2 closed yesterday, Nanyang Primary School and Nan Hua Primary School had more applicants than vacancies available. Last year, three schools were oversubscribed at this stage: Anglo-Chinese School (Primary), Henry Park Primary and Nanyang Primary.

At each registration phase, if the number of applicants is higher than the number of vacancies, schools usually have to conduct a ballot for applicants. Vacancies that are left unfilled in each phase are carried over to the next phase.

This year, Nanyang Primary had 23 children applying for 12 vacancies in this phase, while Nan Hua Primary had 23 children registering for 19 vacancies. Nanyang had 390 vacancies in total, of which 338 are already taken. Nan Hua had 240, with 181 already filled.

Earlier phases are for siblings of current pupils and children of alumni association or school advisory committee members. Phase 2A2 is for children whose parents or siblings are former pupils, or whose parent is a school staff member.

The next phase, 2B, is for children whose parents are school volunteers, active community leaders or have ties with church or clan associations directly connected with the schools. Registration starts next Monday and ends on Tuesday .

In 2014, a rule was introduced requiring all primary schools to set aside 40 places for children in the later stages. The 40 places will be split equally between children registering in Phases 2B and 2C.

Phase 2C is for children with no ties to schools. For this phase, parents can also register their children through the P1 Internet System (P1-IS), instead of going to their school of choice to register.

A new school, Fern Green Primary in Sengkang, opens next year and is accepting P1 registrations.