Complicated school admission rules are leaving parents confused and at risk of making unrealistic applications, it has been suggested.
There is "incredible" variation in school admission policies, with individual schools demanding different information and using different criteria for admitting pupils, according to the The Good Schools Guide.
As a result, mothers and fathers are forced to conduct "labour-intensive" research and fill in reams of paperwork, it warns.
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Calling for an overhaul to simplify the system, the guide sets out a series of tips for parents – including a warning that leaving spaces on application forms means a risk that councils will fill in the blanks with the least popular schools.
Elizabeth Coatman, state education specialist at The Good Schools Guide, said: "It's a matter of making unrealistic choices."
She added: "If you put down all schools that you haven't got a hope of getting a place at, because you live too far away, or you don't meet the place criteria, then the authority won't be able to offer you any of your schools and so they will offer you the nearest school with a vacancy."
It is sensible for parents to include their local school – such as the one they are in the catchment area for, even if it is as their final choice, Ms Coatman said, adding: "At least you know you'll get a school that you can live with."
Applications to secondary school
The warning comes as families across England complete secondary school application forms ahead of the 31 October deadline.
Official figures show that this year, across England, there were 604,500 applications for secondary school places – up 3.7 per cent on last year.
Eight in 10 families (80.9 per cent) got their first preference of secondary, down 1.2 per cent on 2018.
About 28,000 families (4.6 per cent) were offered a place at a non-preferred school.
Under the current system parents are typically asked to give between three and six preferences of school on their application forms.
Schools with good results and reputations are most likely to be over-subscribed, The Good Schools Guide says, but can also have complicated policies setting out how they will decide which pupils will be given places –known as over-subscription criteria.
Ms Coatman said: "The variation in admissions policies is incredible. What one school demands of an applicant may be very different from the requirements of an apparently similar school down the road.
"I have every sympathy for parents who find getting to grips with the complexity of some state school admissions policies gives them a headache. We have seen one that runs to 12 pages.
"Setting aside time to research options and work out the likelihood of a successful application, not to mention fathoming the further obligations and paperwork as required by some schools, is labour intensive and no doubt favours certain sections of society."
Tips for parents
The Guide says that parents should research all the options, and read the admission policies of their preferred schools carefully.
"If your child doesn't fit the oversubscription criteria and the school is over-subscribed year on year, then look elsewhere," it says.
For example, it says, while faith schools are often popular, they also often expect extra paperwork and prioritise children who have been baptised and are from church-going families.
"If the school is always oversubscribed and you can't claim to match their requirements, you have little chance of a place."
The Guide also warns: "It is not wise to leave blanks on the form or list one school multiple times. This does not mean that you are limiting the local authority to fewer options.
"It means they will fill in the blanks with other schools, which will inevitably be the least popular ones."
Ms Coatman said: "In an ideal world, there would be one common, national set of over-subscription criteria for all community schools, free schools and academies, with another simple set for all kinds of faith schools."