The Hong Kong system is divided into three types of schools. There are public schools, subsidized establishments and private international ones. There are 600 public primary schools, as well as roughly 500 public secondary academies, providing free education to Hong Kong children.
But there are about 40 private international schools, which are the most popular among wealthy parents. These are the hardest to get into even if you can afford the one-off cost of the debentures and the high tuition fees.
Only those children with "permanent resident status" in Hong Kong, and those whose parents have employment visas issued by the city, are eligible to apply for schools, according to local regulations.
"It is hard to calculate the proportion of students with a mainland background in Hong Kong schools," Lai Zhifeng, a senior manager with wealth management and insurance firm AIA International Ltd and a member of the Hong Kong Academy of School Managers, said. "Some are born in Hong Kong and others move here with their parents. Generally speaking, there are more of them entering local schools, especially those highly competitive private international establishments."
Before 2012, mainland pregnant women gave birth to more than 200,000 babies in Hong Kong. These children became known as shuangfei－babies born in Hong Kong from parents that had no connection with the city. These children were granted "permanent resident status" and were allowed to be educated in Hong Kong.
But tighter government immigration controls in the city, brought in three years ago, have closed that loophole. Even so, with more mainland Chinese professionals and their families moving to Hong Kong, finding a school place has become difficult.
"Many people come to me and ask about how to get their children into one of the leading schools," Lai said, referring to the wealthy mainland families that target the exclusive establishments such as the Victoria Kindergarten. This was the pre-school that Hong Kong's richest man Li Ka-shing sent his granddaughter to.
But it is not just the elite educational centers that are proving extremely popular and difficult to get into. Middle class schools are following the same trend in the city.
While the debenture at a famous school usually costs hundreds of thousand of Hong Kong dollars, the tuition fee for an international establishment is at least HK$100,000.
"Each international school has its own criteria for admission, and they cannot be explicitly explained," said Kwok of BA Marketing. "Children need to pass an interview, competing with their peers to get a place. While some schools offer debenture holders a confirmed position, some do not."
The ISF Academy, a popular international school among mainland parents, pointed out on its official website that "priority" will be given to debenture holders and siblings of students.
"Nominees of capital note holders and siblings will be given an opportunity for a reassessment should they not pass the first admission assessment," the ISF website highlighted.
A school's spokesperson declined to reveal how many debentures are issued every year or the acceptance rate of note holders.
