According to the Family and Childcare Trust study, parents spend £7,500 a year on part-time childcare for two children - which is almost 5% more than the average mortgage bill.
The information was provided by councils in England, Wales and Scotland - who were asked to provide the cost of 25 hours and 50 hours of childcare in nurseries/with childminders.
The report found that a family with a two-year-old attending nursery part time, and a five-year-old attending an after school club would be forced to spend £7,549 a year.
The UK average annual mortgage is put at £7,207.
But Childcare minister Elizabether Trust maintains that the cost of childcare has remained the same for the first time in 12 years.
'Costs for the majority have actually fallen,' she said.
'This means more parents are able to access affordable childcare and support their families.'
Head of Policy at 4Children said: 'The cost of childcare remains a major challenge for many families, resulting in some parents getting into debt and others having to give up or being prevented from taking up work.'
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