The cost to families for part-time childcare is more than the monthly mortgage repayment, figures show.
According to the Family and Childcare Trust study , parents are spending more than £7,500 a year on part-time childcare for two children - around 4.7% more than the average mortgage bill.
Those with two children in full-time childcare are hit with an annual bill of £11,700 - 62% higher than the average yearly mortgage bill.
Its also says some families may be spending more on childcare than they do on their weekly shopping.
Information for the report came from family or children's information services at councils in England, Wales and Scotland.
Each local authority was asked to give the cost of 25 hours and 50 hours of childcare as provided by nurseries and childminders.
They were also asked to give figures on the average cost of 15 hours childcare in an after-school club, or for a childminder picking youngsters up from school.
It found a family with one two-year-old child attending nursery part-time and a five-year-old in an after-school club will be forced to spend £7,549 a year on average.
This is higher than the UK average annual UK mortgage, which the report puts at £7,207.
Education and childcare minister Elizabeth Truss insisted the cost of childcare in England had stabilised for the first time in 12 years.
"In fact, once inflation is taken into account costs for the majority have actually fallen," she said.
"This means more parents are able to access affordable childcare and support their families.
"These reductions contrast with rising costs in Scotland and Wales, highlighting the difference this Government's reforms are making."
The Department for Education said that the survey shows that the cost of nursery for a child over two was now £106.19, compared to £106.52 per week last year, which it said was a 2% reduction in real terms.
Dr Steven Toole, head of policy at 4Children, said: "The cost of childcare remains a major challenge for too many families, resulting in some parents getting into debt and others having to give up or being prevented from taking up work.
"Recent 4Children research shows the scale of the struggle parents face with childcare, with one in four saying that affordable, flexible and accessible childcare would make the most real, positive difference to their family life."
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