Young children will have an extra year of education under a new plan from both the NSW and Victorian governments.
NSW Premier Dominic Perrottet and his Victorian counterpart Daniel Andrews want to introduce the new year for four- and five-year-olds.
For NSW families, it will begin from 2030 and fall a year before what is known as kindergarten.
Victoria plans to start from 2025, with a year of new schooling before what is known as prep.
Children would attend five days a week and it would be free of charge.
"It will mean that, in the next 10 years, every child in Victoria and NSW will experience the benefits of a full year of play-based learning before their first year of school," the premiers said in a joint statement.
"At the same time, it will benefit hundreds of thousands of working families."
The exact model is yet to be developed but both leaders have committed to working together to achieve the reform.
In both states, the year will be delivered in a preschool setting.
NSW Education Minister Sarah Mitchell said data showed preschool numbers had been increasing but most children only attended two days a week, while this policy would insist on five days a week.
"So this is about really turbocharging that — to offer the five days a week we know just makes such a difference," Ms Mitchell said.
She said the government would build more community preschools and planned for them to be next to primary schools or on their grounds.
The pre-kindergarten year is unlikely to be compulsory when it is first introduced.
"Universal pre-kindergarten is something I have been working hard to bring to NSW for a number of years, having seen the benefits of it for children and families in countries like Canada," Ms Mitchell said.
"When you look at the Canadian model that's on offer, 95 per cent of parents take up that opportunity."
She acknowledges there are early childhood educator shortages and childcare accessibility issues that mean it will take time to implement this plan.
In Victoria, 4-year-old kinder will be rebranded as 'pre-prep' and the weekly hours of play-based learning will be phased up from 15 to 30, starting in 2025.
Kinder will be made free for 3- and 4-year-olds from 2023. The government currently subsidises kinder, but costs still vary wildly.
The Victorian government will also fund 50 affordable childcare centres in areas of high demand.
Victorian Minister for Women Gabrielle Williams said the plan would benefit children and mothers in particular.
"Pre-prep program will provide children with more access to play-based learning which consistently shows positive impacts for vocabulary development, for reasoning, for early numeracy," she said.
"It's also about enabling the economic empowerment of women — enabling women to get back to work if that's what they choose to do, which can have an enormous impact on those long-term financial outcomes for women."
The NSW government has committed to spending $5.8 billion over the next 10 years, some of which will be set aside in next week's budget.
"This budget is all about investing in a better future, and setting our kids up for success is priceless," Treasurer Matt Kean said.
"This reform will deliver intergenerational results for our kids and our economy."
The Victorian government has set aside $9 billion to be spent on the reform over the next decade.
A consultation period will now begin.
