The government has temporarily overhauled funding of the sector, guaranteeing its portion of fees based on enrolments in early March, and banning centres from charging parents the difference.

The move was designed to make childcare free to parents during the pandemic.

But it effectively slashed the income to services.

Education Minister Dan Tehan said the new system was calibrated to work in tandem with the JobKeeper wage subsidy scheme.

"There will always be some unintended consequences," he told Sky News on Monday.

A one-month review of the system will start next week.

"One of the things we'll be looking at is how we account for those centres who might use a large proportion of their staff (who) aren't eligible for JobKeeper," Mr Tehan said, mentioning educators on foreign worker visas.

"And for those centres who have seen their attendance rate at 100 per cent or even increase further, we'll be looking at that during the review as well."

Across the sector, attendance stands at an average of 40-60 per cent.

The government has released a further $27 million in grants to help those centres that have had an increase in demand for places and those which aren't eligible for JobKeeper.

Australian Associated Press