A report by a cross-party group of councillors said the cost of uniform was "too high", a "barrier" to education and was leading to bullying and truancy among pupils.
A sample of 16 schools across the Wakefield district suggested the average cost of a uniform, including PE kit, was £208 for parents of primary school children, rising to £267 for secondaries.
The report criticised local schools for a "lack of transparency" over their uniform pricing and for insisting on branded clothes with academy logos on, rather than allowing generic uniform items bought from the high street.
The investigation also found:
- Most schools have a single uniform supplier, which is restricting competition and keeping prices high
- Some schools do provide support to families on low incomes, but this is "not always well publicised".
- The price of girls' trousers at some schools was higher than boys' trousers. The reverse was the case in other schools.
- Primary schools have a "more relaxed approach" to uniform than secondary schools
- Schools are "failing to check on family circumstances" when a child attends with the wrong uniform, with some pupils forced into isolation when they do.
The government brought in new guidance last year, which says schools should keep the number of branded items to a "minimum" and ensure second-hand uniform is available to parents.
But head teachers do not have to fully comply with that guidance until the summer of 2023.
Sally Kincaid, from the National Education Union's (NEU) Wakefield branch, said the uniform issue was becoming a "minefield" for parents.
Ms Kincaid, who also sat on the working group, said: "If schools want to insist on a dress code, they should be keeping the prices for it absolutely minimal and they should be providing support to parents who need help to pay for it.
"There are some secondaries who do give pupils a free uniform when they start Year 7, but we know how quickly children of that age outgrow their clothes, so it's a token gesture really."
In their written findings, the group also said: "The fact that children grow out of things quickly and can lose or damage their uniform, then the cost of providing uniform can become a significant financial burden, making even uniform clothing bought from high street retailers prohibitive.
"Wearing the wrong/ill-fitting uniform singles a child out from the rest, increasing the risk of them falling victim to bullies or playing truant because they do not feel they fit in.
"Not only does this impact on the child’s education but may also affect their health and wellbeing."
The report recommended academies provide emergency funding for parents in "financial hardship" to spend on uniform.
It also suggested that Wakefield Council make cash available for the same purposes until the end of the 2022/23 academic year.
Responding to the report and the criticism of schools, James Bowen from the National Association of Head Teachers (NAHT) said: "It’s important to remember that a large number of schools already work extremely hard to ensure that their uniform is affordable for families.
"Many schools also run schemes to provide support for families who might be struggling with the cost of uniform.
"That being said, it’s important that uniform remains as affordable as possible in every school.
"We know that an increasing number of families have come under financial pressure due to the pandemic, so measures that could reduce the cost of uniform are welcome."
Local Democracy Reporting Service