The Office of Fair Trading (OFT) has asked schools to look into the cost of school uniforms.
Nearly 30,000 state primary and secondary educational institutions have been contacted in an effort to get policies reviewed whereby items can only be purchased from certain retailers or suppliers.
The OFT thinks that parents could collectively save millions of pounds if these guidelines were relaxed.
A survey by the body found that 74 per cent of state schools currently have restrictions in place on where uniforms can be purchased.
Susan Oxley, Assistant Director in the OFT's Goods and Consumer Group, said: "When schools require that uniforms are bought from a preferred supplier or shop it can act as a tax on families."
She added if more competition was introduced into the system, then mums and dads would benefit from better pricing structures.
The main reason advanced by educational establishments for using one supplier is to ensure that all pupils wear consistent, good quality uniforms.
However, the OFT feels this would not be compromised under its plans.