Nearly all children in schools, from reception to Year 11, are required to wear school uniform, while the vast majority are required to have a physical education (PE) kit to a certain specification. This report presents findings from the Cost of School Uniform 2023 study, which was commissioned to assess whether the relative cost of school uniforms has changed since 2015 and to assess the impacts of the statutory guidance on the Cost of school uniforms. The statutory guidance was intended to ensure that uniform, PE kit, and branding requirements are not onerous for parents/carers, and that the cost of school uniforms and PE kit is reasonable, secures value for money, and is not an obstacle to children attending the school of their choice. A telephone survey of a representative sample of 1,207 parents/carers of children aged 4 to 16 attending state funded schools in England was used, along with fieldwork conducted between November 2023 and January 2024. Subgroup analysis was undertaken to understand key differences based on school phase, school type, household income, and eligibility for free school meals. The 2023 survey findings suggest that good progress is being made in respect of the aims of the guidance. Compared with 2015, parents/carers were more likely to report that they were able to purchase school uniform and PE kit from somewhere other than from designated shops and/or from the school, and this has helped to bring expenditure down, as average expenditure was lower among parents/carers who reported that they were not tied to single sources. The findings also report a significant increase since 2015 in parents/carers reporting that their child's school makes second-hand school uniforms available for purchase. Whilst there is clear evidence that the financial demands on parents/carers with respect to school uniform requirements are lessening, the survey shows that parents remain concerned about the cost of school uniform.