Wellingtonians could save hundreds of dollars a year on public transport thanks to a tax-free scheme rolling out across the capital, if their employers opt in.

Greater Wellington Regional Council is introducing the scheme in partnership with fintech firm Extraordinary, which has built a payroll-based product allowing Snapper top-ups to be paid from pre-tax income. The council estimates users could save about 30 percent on their daily commute, or up to $900 a year.

Regional council chair Daran Ponter said the scheme was "the single biggest fares change" Wellington had seen in years, and would put pressure on neighbouring regions to follow. About 40 large employers have already registered interest.

Critics note that the scheme rewards salaried workers more than casual or shift workers, and have called for matched fare reductions for low-income riders.