Children caring for a relative could have their education and job prospects permanently damaged, a charity warns.
The Children’s Society says one in 12 young carers in England spend more than 15 hours a week caring for a parent or sibling, and one in 20 miss school.
Its new report says that young carers are 50% more likely to have special educational needs or an illness.
A Department for Education spokeswoman said schools have a “key role in supporting young carers”.
Census figures due out on Thursday will show how many young people are carers.
But the Children’s Society warns any official figure is likely to be “just the tip of the iceberg” and calls for more government support and recognition for these young people.
“Many young carers remain hidden from official sight for a host of reasons, including family loyalty, stigma, bullying, not knowing where to go for support,” the charity says in its report, Hidden from View.
The study, funded by the Big Lottery Fund, analyses government data that tracked 15,000 children in England aged 13 and 14 between 2004 and 2010.
It found young carers had “significantly lower” educational attainment at GCSE level – the equivalent to nine grades lower overall – than their peers.
The study found average annual income for families with a child carer was Â£5,000 less than families that did not have a young carer.
Young carers were more likely than the national average to be “not in education, employment or training” (Neet) between the ages of 16 and 19.
Young people from black, Asian or other minority ethnic communities – and for whom English is not a first language – were twice as likely to be a young carer.
The Children’s Society says that, despite improved awareness of the needs of young carers, there is no strong evidence that young carers are any more likely than their peers to come into contact with support agencies.
The report says: “Children must be allowed to thrive and enjoy their childhoods, not be forced to take caring roles that are too often inappropriate.”
Children’s Society chief executive Matthew Reed said: “Our new analysis shows that caring can cost children dearly. They are missing out on their childhoods and school, gaining fewer qualifications and therefore are less likely to earn a decent living.
“All children must be allowed to thrive and enjoy their childhoods. One young person remaining under the radar, out of sight of the very authorities there to support them, is one too many.”
A Department for Education spokeswoman said: “Schools have a key role in identifying and supporting young carers. We must ensure that every child has the opportunity to meet their full potential.
“We recently announced that young carers will be involved in the training of school nurses, so they know exactly what support they should offer and can champion their needs.
“We are also funding the Children’s Society and Carers Trust to encourage children’s and adult’s services to adopt ‘whole family’ approaches to supporting young carers and we have created a specific training guide for teachers to help them to better identify and support young carers.”
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