In KiwiSaver changes, default employer and employee contributions will rise from three to four percent, phased in over the next three years, although members can temporarily opt-out.

The Government's also halving its maximum contribution to $260 dollars - and not extending it to those earning more than $180,000 a year. 

Meanwhile those aged 16 and 17 will become eligible to receive a Government contribution. 

Nicola Willis says it'll encourage Kiwis to save more for their first home and retirement.