Girls not Brides calls for ban on child marriages in Britain A global campaign to end child marriage is focusing on Britain, where campaigners say the law fails to protect under-18s. The legal age for marriage in England and Wales is 18, but children aged 16 and 17 can marry with parental consent. Activists believe consent can mean coercion. Girls Not Brides, a global partership of more than 1,000 organisations seeking to end child marriage, is calling for weddings of under-18s to be made illegal. Its proposals would include all cases where either party is British or lives in the UK.