MPs will scrutinise the Childcare Service website as part of an inquiry into how childcare can affect the economy.
The cross-party Treasury Committee will examine past failures of the website, which allows parents to apply for 30 hours' free childcare and the Tax-Free Childcare scheme, which gives eligible parents or guardians up to £2,000 per child towards childcare costs each year.
The committee will also look at how access to childcare can influence how efficient the UK workforce is, and consider the overall set of Government initiatives that aim to make childcare affordable.
MoneySavingExpert.com has reported on several problems with the Childcare Service website, such as when Tax-Free Childcare was delayed for older children in November, and earlier this week, when a glitch meant several parents were told they weren't eligible for 30 hours of free childcare.
We also reported in August that there had been 1,000 complaints about the website in the three months following its launch last April.
Website problems a 'cause for concern'
Commenting on the launch of the inquiry, Treasury Committee chair Nicky Morgan MP said: "High quality and affordable childcare is important for getting parents into work and supporting working families.
"There had been reports of problems with the HMRC-run Childcare Service website, which has been a cause for concern. We'll examine the impact of these failures on the take-up of Government initiatives that aim to make childcare affordable."