In KwaZulu-Natal, the head of the Governing Body Foundation, Tim Gordon, said there was a huge demand for places at public schools, particularly in urban areas.
"Our information suggests that this is especially in the Umlazi and the Pinetown education districts that the pressure is building up, and pre-eminently in the suburban schools."
Gordon said the Umlazi district included parts of suburban Durban, and the Pinetown district incorporated Westville and surrounding suburbs.
"Hundreds of schools are affected - traditional schools such as Durban Girls High, DHS, Glenwood, Westville Boys and Westville Girls, Danville and Northlands - north of Durban and Hillcrest schools ... there are many, many more.''
Gordon said rural families often moved to urban areas for a better lifestyle and job opportunities.
"A factor is the perceived educational quality gap between poor rural and township schools, and quality urban and suburban ones.
"There are exceptions, of course, but in the main this perception is a reality, and parents will go to great lengths to get their children into what are seen as the best schools."
He believes the demand for space in urban public schools will increase until the education department focuses on "improving the quality of teaching, educational delivery, proper facilities, teacher discipline and attendance, effective curriculum coverage".
These are Gauteng's most popular public schools
Top schools get swamped with applications for classroom space
About four in every 10 high school applicants for next year applied to a mere 5% of schools in Gauteng.
According to Gauteng education MEC Panyaza Lesufi, by November 1, 98928 grade eights had been placed for next year.
But, 40,292 applied to only 34 of the roughly 620 high schools in the province. All these high schools received more than 1000 applications each, but can accommodate only 8,300 pupils in total.
The 34 Gauteng high schools that got more than 1,000 applications for grade 8:
The Gauteng education department opened its online registration system for late applications for grades one to eight on November 1.
Lesufi said 402 schools had "received applications beyond their capacity" and are unavailable for late applicants.
There are 1,397 primary schools in the province and 123,450 grade ones had been placed by the start of November.
Only three primary schools received more than 1000 applications for grade ones. They were Laèrskool Akasia and Laerskool Theresapark, in Pretoria, and Bryanston Primary School, in Johannesburg.
The 20 Gauteng primary schools that received the most applications for grade 1:
In total, 77% of the 285,834 Grade 1 and Grade 8 applications made before November had been accepted. This means more than 65,000 pupils who applied early still need to be placed in a school.
The interactive map below shows where the schools that were full by November 2017 are (red dots), and where those that were therefore likely to still be open for late applications (yellow dots).
Hover over the dots and zoom in to explore the schools:
Gauteng education spokesman Steve Mabona did not respond to questions about why these high schools were so popular, how many additional applications they received in November during the late registration period, or how many pupils had been placed by the end of the month.
'Huge demand'
In the Western Cape the situation was similar.
Provincial education spokesman Jessica Shelver said some schools received five times more applications than the number of places they had available.
Claremont High School this year received the most applications, 1,806, followed by Mondale High School with 1,366 and Westerford High School with 1,130.
She said the department had been "inundated" with demands by parents that their children be placed in a school of their choice or closest to their home.
School governing bodies determine the admission policy of a school in line with the constitution and legislation.
Shelver said some schools included proximity to an applicant's home as a criterion but that it was rarely the sole decider. She advised parents to apply to many schools.
"It is surprising how many parents apply at only one school each year."
Population growth and migration to the Western Cape is piling stress on schools, housing, medical facilities and jobs - and Cape Town can only expand northwards.
According to Shelver, every pupil costs the province R12,000 a year.
"This includes their norms and standards allocations and educator salaries averaged on a per learner basis."
Since 2012, an average of 23,603 pupils from other provinces entered the Western Cape schooling system. More than four of every five pupils (80.74%) were from the Eastern Cape.
In KwaZulu-Natal, the head of the Governing Body Foundation, Tim Gordon, said there was a huge demand for places at public schools, particularly in urban areas.
"Our information suggests that this is especially in the Umlazi and the Pinetown education districts that the pressure is building up, and pre-eminently in the suburban schools."
Gordon said the Umlazi district included parts of suburban Durban, and the Pinetown district incorporated Westville and surrounding suburbs.
"Hundreds of schools are affected - traditional schools such as Durban Girls High, DHS, Glenwood, Westville Boys and Westville Girls, Danville and Northlands - north of Durban and Hillcrest schools ... there are many, many more.''
Gordon said rural families often moved to urban areas for a better lifestyle and job opportunities.
"A factor is the perceived educational quality gap between poor rural and township schools, and quality urban and suburban ones.
"There are exceptions, of course, but in the main this perception is a reality, and parents will go to great lengths to get their children into what are seen as the best schools."
He believes the demand for space in urban public schools will increase until the education department focuses on "improving the quality of teaching, educational delivery, proper facilities, teacher discipline and attendance, effective curriculum coverage".