Letters are being posted to hundreds of thousands of parents across England telling them which secondary schools their children will attend.
Competition for the most popular schools is stronger than ever
Local authorities have allocated places for around 660,000 children aged 10 and 11 beginning next September.
Government figures suggest some 15% or 99,000 will not be going to the school they wanted, and many will appeal.
The letters are expected to start arriving on Friday, but some parents will find out by e-mail on Thursday.
Councils have spent months working through the choices specified by pupils and their parents.
The proportion of parents appealing against the decision of their local authority has doubled since 1993, although it has declined a little in recent years.
Last year, out of 676,420 secondary school admissions, there were 62,750 appeals of which 16,340 were successful.
Around one third of the appeals heard each year are successful.