The 2007 DCSF Attendance Sweeps Guidance for England says:
School attendance sweeps involve stopping any young person believed to be of school age, whether accompanied by an adult or not. The intention is to establish whether or not the young person is registered at school and, if so, whether he/she is out of school legitimately.
Sweeps will generally involve a police officer and an Education Welfare Officer. Since the home educated child is not a registered pupil, the parent cannot be committing any offence to do with registered pupils being absent from school. In addition, the child cannot be committing an offence because ensuring attendance of registered pupils is the legal responsibility of the parent and not of the child.
You are within your rights to tell the truancy sweep personnel that your child is home educated following section 7 of the 1996 Education Act and that therefore you should be allowed to go on your way because you are not the target of the sweep.
Some members opt to carry a laminated Education Otherwise “Truancy Card”, particularly if young people are out and about on their own during school hours. You don't have to give your name and address unless the police officer has further specific concerns which are communicated to you during the encounter.
Some Education Welfare Officers may not know that home education is legal and some may believe that we have to be “registered” or “approved”. You should make them aware that the Government states very clearly that we don't have to register.
Please see Education Otherwise Information Sheets on Deregistering a Child from School (England), The Law and Home Education in England and Wales and Children Missing Education (England)