"It is possible to negotiate with the school for part time attendance until they reach compulsory school age. But schools don't always make this easy. If you don't send your child until they are 5, the school is not obliged to hold the place open."
Actually, I believe you can choose to defer your child's start in reception until January (April for children born between January and August), and the school has no say in this, and they are obliged to hold the space open.
If you would like your child to attend from September, but part-time, then indeed you will have to negotiate with the school. Usually they should be amenable to finding a solution that works, as your alternative would be to just not send them at all until January.
So in your particular case, you apply for a school place by 15th January when your child is (just) four. You are allocated a place in April. Your child can start in September, at age 4 (nearly five). You can accept that place but choose to not start until January, when your child will be just five. Or you can accept that place and arrange with the school that your child will only attend part-time until January.
School is not compulsory. It is every child's right to have an education, but it is up to the parents to decide which form this education should take. It is the state's obligation to offer your child a space at a school if you ask for one. Therefore you can choose to home educate your child until whichever age you deem appropriate for them to start school. Then you apply for a school place and the state is obligated to find one.
There are a few things to consider with this approach:
- In the highest probability, your child will join their 'correct' cohort, that is, if you decide for your child to start at age 6 (nearly 7), they will have to start in Y2. Whilst academically, your child may be at the same place as their new classmates (or they may not, and have lots of catching up to do), the others will have had two years to get to know school routines and structures and discipline.
- You most likely won't be able to choose a school. Popular schools will be full, so whilst the state is obliged to find a space for your child, it may well be at a school you don't like and is 30 minutes in the wrong direction. (However, you may not have a real choice in schools anyway, if you live in a very oversubscribed area. And if you live in a 'undersubscribed' area, you'd have good chances to get a space in a school you do like/is near by, even in Y2)
- Most nurseries/childcare settings will take your child until they turn 5, but not beyond that. So if you decide to delay your child's entry to school beyond then, you probably won't have access to easy outside childcare.
It is all different if you're considering private schools! E.g. the German School in Richmond has a later starting date (I think age 5/6) and does not expect children to have been at school before. Other private schools require registration years before the child is due to start. Some have several entry points, others not. If you're considering private, you'll have to check out each individual school's requirements.