The Bill was introduced by Labour MP Mike Amesbury in February last year. It has now received Royal Assent, which is where the Queen agrees to make it law, after passing through Parliament and the House of Lords.
Full guidance on how schools will enforce the law will be published in autumn this year.
Mark Russell, Chief Executive of The Children’s Society, added: “We are thrilled this new law has passed and we thank Minister Gibb and the Department for Education for their support. This legislation will be vital in ensuring that school uniforms become more affordable for families across the country.
“Young people told us back in 2014 that high-priced school uniforms had a huge impact on their ability to make the most of their education. We hope this new law will make children feel more equal to their classmates and make life easier for struggling families.”