Nearly 200 pupils in Hertfordshire have been left without a secondary school place in September.
Hertfordshire County Council has been unable to offer a place to 189 children and more than 1,000 others have been given a place, but not at any of their four selected options.
One parent said the authority “just needed to do a basic bit of maths”.
The council has asked parents to “stay calm” and said all children will eventually receive a place.
Some 14,714 children applied for secondary school places in the next intake.
The authority said a “bulge year” for births between September 2007 and August 2008 means it had 460 more applications this year than last year.
It is the first year since statistics have been published that the council has failed to allocate all children with any school at this first stage.
St Albans parent, Josie Madoc, said the council told her that, at the moment, it could not offer her daughter a place anywhere in Hertfordshire.
“How is this the case? This isn’t a third world country,” she said.
“They knew this was a high year. This wasn’t a surprise – these kids were born 10 years ago.
“They just needed to do a basic bit of maths.”
The authority said the main issue was the funding allocation from the government for the new Katherine Warington School, being built in Harpenden, which came in too late for the school to be included in the council’s coordinated application process.
Parents in that area who expressed an interest in the new school had to fill in a separate application form in a parallel process and as a result have been given duplicate places – one at the new school and one at another. Once parents have made their final selection, at least 180 places will be freed, the council said.
Terry Douris, Conservative cabinet member for education asked parents to “stay calm” and said everyone will get a school place.
“The first run of the continuing interest list will sort out all of the anomalies and we are very confident we will be able to provide, particularly in the Harpenden and St Albans area, a secondary school which is as local as possible to them.”