"Putting ballot boxes in supermarkets and malls will make it easier for people to vote. It's important that ballot boxes are placed where people are going about their normal business and can therefore accommodate voting more easily into their busy lives."
Other changes include introducing same-day enrolment for voters and moves to make it easier to vote from overseas.
About 19,000 people's votes weren't counted in 2017 after they showed up without having enrolled on election day.
The overall voter turnout was 79.8 per cent - the highest turnout since 2005.
But National Party electoral law spokesman Nick Smith said the Government had ignored long-standing conventions about consulting the Opposition on electoral changes for its own benefit.
"This is the sort of conduct we expect from banana republics and not a respected long-standing democracy like New Zealand," he said.
He said National had only learned of the changes on Thursday and had not been given the details.
"These electoral law changes set a dangerous precedent and highlights the vulnerability of our democracy."