The mum of a schoolboy who missed seven months of school has accused the council of "mind-boggling ineptitude".
James Yalçın was rejected by local secondary schools for the majority of the school year and is only able to get two hours of teaching a day due to the error.
Mum Sarah Yalçın from East London says the 12-year-old has become "depressed" stuck at home without any contact with other children.
The error, Sarah says, is down to a care plan which was issued for James back in 2018 because of his diagnoses of epilepsy, ADHD, ODD, dyspraxia, autism, and sleep apnoea, meaning he requires specialist help at school.
But according to the mum, James' behaviour has massively improved since five years ago - at which point he was biting people ad escaping lessons - and the Education, Health, and Care plan (EHCP) has not been updated to reflect that.
"It's absolutely soul destroying," she told MyLondon.
"How do you explain to your children why you can't go to school? Even when he was ill he would want to go, he loved it.
"At the moment I am trying to keep my job as best as I can, my mum and sister are taking time off work to look after him.
"It's not fair on him, it's like pass the parcel, it's aggravating.
"It's just mind blowing, it's just not fair. If it was the other way around and I was keeping him out of school I can imagine the fines I would be getting.
"I would be chased after and have council officers at my door."
In May last year, Sarah was receiving rejections for secondary schools and met primary school teachers for an emergency meeting where it emerged Waltham Forest Council had not updated the EHCP since 2018.
During James' time at the primary school, Sarah says seven different Assessment, Planning and Review Officers had been assigned to his case - which she suspects may be why his case was being signed off without being properly checked.
After alerting the authority to the error she was told new applications had been made with an updated plan, and waited only to hear nothing back.
When this was chased up last May, James' primary school discovered the plan had still not been updated.
A council officer for special educational needs told Sarah, meanwhile, that had been "no response" from James' parents or school to correct the error, meaning it stayed the same.
Sarah claims this represents an admission the wrong EHCP was sent for a second time.
An updated EHCP was issued in November 2022 - four years and nine months after the previous issue - after frustrated Sarah appealed the case.
The law requires all Education, Health and Care Plans are reviewed by the local authority at least annually.
With the old plan allegedly sent out with applications twice, Sarah admits she can understand why James was rejected.
"I can imagine schools having a problem with a 12-year-old running around biting and kicking and trying to escape," she said.
"I can totally understand why they didn't give him a place, but it means he's still waiting to go to school."
James at one point was offered a place at a school in Leyton, a half an hour bus journey from his home, which Sarah said just wouldn't have been do-able for her as she juggles her job and her other daughter, Jasmine, who herself has autism.
Jasmine, 10, was recently awarded her preferred school choice, but not without the same difficulty James has faced.
Cllr Alistair Strathern, Cabinet Member for Children and Young People, said: "We are aware of the family’s situation and we continue to work with them to achieve a positive outcome, which follows the statutory process of consulting with schools as to whether they are able to meet the needs of the children.
"On occasions, this process can lead to delays and we engage with families to minimise any disruption to learning.
"Ensuring that children with complex needs receive places in suitable schools is a national challenge.
"We are determined to do all we can to ensure all of our children and young people have the chance to benefit from a good start in life in Waltham Forest so they have the tools they need to fulfil their potential."
