Statistics published by the Department for Education show that, based on local authority data, an estimated 202,783 children were in a 30 hours place between September and December 2017.
It is the first time a figure for free childcare take-up has been published, with previous data only revealing the number of eligibility codes that had been issued and how many had been validated.
The DfE said latest data from councils shows that a total of 224,885 eligibility codes were issued to parents for the autumn term, of which 210,863 (94 per cent) were validated.
The total number of children in a 30 hours place is equal to 90 per cent of the total number of codes issued.
The statistics also reveal that a total of 305,691 eligibility codes have been issued for the second term of the initiative, the spring term, of which 224,988 (74 per cent) have so far been validated. The DfE said it has a target of issuing 310,000 codes for the spring term.
Children's minister Robert Goodwill said the figures show how popular the 30 hours offer has been with parents since being rolled out nationally in September.
"In its first term around 202,800 children were in a 30 hours' place, with over 305,000 already signed up to access the offer for the next term starting in January," he said.
"We are making excellent progress in our mission to ensure as many families as possible have access to high-quality, affordable childcare."
However, the Pre-school Learning Alliance said the figures show that parents continue to face "huge regional disparities" in the availability of 30-hours places, pointing to the fact that in 12 local authorities less than three-quarters of children who had been issued 30-hour codes had taken up places.
Neil Leitch, chief executive of the Pre-school Learning Alliance, said: "It cannot be right that parents in certain areas of the country are facing such a struggle to access places, as these figures suggest.
"Given that the autumn term is always the quietest for childcare providers, the pressure on places is only going to get worse, and so many parents looking forward to accessing the scheme next term may well be left disappointed.
"What's more, what these figures don't reveal is how many parents with validated codes are receiving genuinely ‘free' childcare, and how many are having to subsidise their places by paying for ‘voluntary' extras.
The government knows full well that inadequate sector funding has forced many childcare providers to rely on additional fees and charges to stay afloat, and yet it continues to promote this offer as free, ignoring the fact that it is parents and providers who are having to fill this funding gap."
Purnima Tanuku, chief executive of National Day Nurseries Association (NDNA), said it is unclear how accurate the figures for September to December are, as 41 per cent of local authorities provided estimates because final data was not yet available.
"If the scheme is supporting more than 202,000 children already, that is good news," she said.
"According to these figures, 305,691 codes have been issued for the January term, putting huge pressure on providers who are already stretched by delivering this offer which is underfunded by central government.
"Local authorities will need to support the early years sector to deliver this significant increase in places.
"We are also concerned that only 74 per cent of the new codes have been validated by providers. This could be a sign that nurseries are restricting the amount of 30 hour places they can offer. Parents could be struggling to get their child a place in a local nursery.
"The pressure on providers is likely to increase again when a further cohort of children tries to join for the summer term. We will be carrying out our own research shortly to establish exactly what is happening on the frontline."