ok, have had it confirmed by email katymc was right
The Early Years Foundation Stage ratio requirements for childminders state:
'where four- and five-year-old children only attend the childminding setting before and/or after a normal school day, they may be classed as children over the age of five for the purposes of the adult:child ratio'
After consultation our Department for Children Schools and Families (DCSF) colleagues have confirmed that their intention was to maintain the status quo. Therefore, despite the wording in the statutory framework of 'before and after a normal school day', we will interpret this requirement in line with DCSF policy intentions.
Where children aged four and five are in full time education (attending ten education sessions per week) they can be counted as over the age of five, for the purposes of the adult:child ratio only. This still applies during weekends and school holidays.
It is important to note you must still deliver the EYFS to rising fives. In addition you must still register on the Early Years Register if you care for children between the ages of birth and the 31st of August following their fifth birthday unless you are exempt from compulsory registration, even if all these children are rising fives.
To be classed as rising fives children must attend 10 sessions of education a week. During any school half-term holiday periods, any children aged 4 who attend school full time will also be classed as a rising five.