The government set out in the 2015 Spending Review that we expect 390,000 children to be eligible for 30 hours’ free childcare. This figure is derived from national survey data taken in January and is an average across the year. Estimates at a regional and local authority level are not available due to the relatively small population that we are estimating within sub-national geographies.
We publish monthly Management Information releases on the number of 30 hours’ eligibility codes issued and validated. These can be found here https://www.gov.uk/government/statistics/30-hours-free-childcare-eligibility-codes-issued-and-validated.
We also publish termly experimental statistics showing the number of children in a place. The most recent publication showed that an estimated 339,974 children were in a 30 hours place in the summer term. The full publication is available here: https://www.gov.uk/government/statistics/30-hours-free-childcare-summer-term-2018.