document: New government guidance says written parental permission must be obtained to use students' biometric data.
  Pupils themselves will also be allowed to refuse to participate.
  Schools can use fingerprinting or face scanning for recording attendance, checking out library books, paying for lunch or accessing school buildings.
  Last year  the Association of School and College Leaders (ASCL) estimated that about 30% of secondaries in England were using biometric data.
  The new advice, which is now being consulted on, will come into effect from September 2013.
  Schools Minister Nick Gibb said the use of biometrics in schools was a sensitive issue and schools should be in no doubt of their responsibilities.
  "I have heard from many angry parents after they have learned that their children's personal data was being used by schools without their knowledge," said Mr Gibb.
  "The new legislation gives the power back to parents, as it requires parental consent before the information can be collected.
  "In the age of the internet, identity and the integrity of biometric data are of increasing importance. Young people need to understand from an early age the sensitivity of such personal data."
  ASCL said schools and colleges had good reason to invest in biometric systems for canteens and libraries.
  The association said the system prevented fraud, stopped money being lost and meant students eligible for free school meals could  take them up without being stigmatised.
  Brian Lightman, general secretary of ASCL, said: "It's right that parents give their consent to use biometric data, just as they do for taking photographs.
  "When the legislation was first proposed, we were looking at a hugely bureaucratic and costly procedure for getting permission which would have been a nightmare for schools.
  "The government listened to concerns and has streamlined the process considerably so that it is as straightforward as seeking consent to take photos or go on school trips.
  "This is a sensible way forward that should reassure parents and meet the needs of schools and colleges."
summary: Schools in England will be banned from taking pupils' fingerprints and using face-recognition technology unless they get permission from parents.