A record number of families are set to miss out on their first-choice secondary school amid a rise in applications, analysis has suggested.
On Friday, more than half a million 10 and 11-year-olds will find out which state secondary school has offered them a place.
One in five children in England and Wales are expected to miss out on their preferred school, because a baby boom in around 2010 has put pressure on places.
Last year, about 620,000 primary pupils applied to secondary schools, the highest number ever.
Demand for places is expected to peak this year owing to a bulge in the primary school population applying for secondary places.
As a result, the success rate for families achieving their first choice could fall to about 80 per cent, projections suggest.
Last year, the proportion of pupils achieving their first choice was 82.6 per cent, down from 83.3 per cent a year earlier, having recovered from a historic low of 80.9 per cent in 2019.
Prof Alan Smithers, director of the Centre for Education and Employment Research at the University of Buckingham, who carried out the analysis, said competition for places was “greater than ever”.
Last year, the proportion of schools full or above capacity rose to 23 per cent, the highest in more than a decade. The figure is expected to increase this year.
Prof Smithers said more places had been on offer this year, but not enough to keep pace with extra demand.
Geoff Barton, general secretary of the Association of School and College Leaders, said: “The number of pupils in secondary schools has been rising in recent years and is set to do so again for 2024-25. It’s therefore inevitable that there will be pressure for places, although the extent of this will vary across different areas.
“Schools and local authorities will have done their best to plan for these population changes and the majority of families will still get their first choice. Where the pressure will be most keenly felt is in schools that are already oversubscribed.
“This is often caused by families moving into the catchment area of these schools, which tend to be located in affluent areas and have positive Ofsted ratings.”
The most competitive region for a family to win a place at their first preference school last year was Lambeth in south London, where only 61.6 per cent received an offer from their preferred school. In the London boroughs of Redbridge and Wandsworth, the offer rate was 63.3 per cent and 64 per cent, respectively.
In other parts of the country, the success rate was much higher. In Rutland, 98 per cent of applicants received an offer from their first-choice school, while in Cumbria and York, the figure was 96 per cent.
A spokesman for the Local Government Association said it was “becoming increasingly difficult to keep up with demand” for places because more schools have become academies, which local authorities cannot direct to expand.
The spokesman added: “Every child should have a fair chance of getting into their parents’ preferred school and councils and schools work extremely hard to try and ensure that as many pupils as possible are allocated their first preference.”
The Department for Education has been contacted for comment.