You should not expect your child's school to agree to a family holiday during term time. The law states a head teacher has the discretion to authorise a students holiday. The school will carefully consider your request and they may take your child's attendance record into account. Schools will not agree to your child missing more than a total of 10 school days for family holidays in any one school year, unless there is a very good reason. However, some schools will not authorise any holiday during term time. Wherever possible, you should take your family holidays during school holidays. Avoid taking your child on holiday at critical times during their education, e.g. at the beginning of the academic year - especially if they change schools - or when your child should be taking exams or tests.
A penalty notice may be issued to parents who have had their request refused by school but still take their child on holiday in term time.
Subsequently the government introduced measures to reduce term time holidays under the Antisocial Behaviour Act 2003 which required local authorities to consider the use of penalty notices as an alternative to prosecution under section 444(1) of the Education Act 1996 - failure to ensure their child's school attendance.
Following this legislation, if a parent takes their children on unauthorised holidays, they may be issued with a penalty notice which gives them the opportunity to discharge their potential liability for conviction under section 444(1) by paying a penalty. The penalty notice is £50 (per parent, per child) if paid within 28 days, rising to £100 with a further 14 days to pay. If the penalty notice remains unpaid, the Local Authority is required to prosecute the parent for the offence of failing to ensure the child's school attendance.