Parents of thousands of children have been asked not to give them a smartphone until they're at least 14 amid fears some were using devices for eight hours a day.
Many schools have already banned smartphones on site but one part of the UK thinks it will be the first to have a countywide policy advising parents against giving children smartphones at home.
Using mobiles is already banned in schools in Monmouthshire, south Wales, but due to a rise in cyber-bullying reports and fears phone use at home is affecting schoolwork, schools are going a step further.
"We've got reports of students who are online at two, three, four in the morning," said Monmouth Comprehensive headteacher Hugo Hutchinson.