The primary teachers' union will discourage members from working at charter schools, but it won't say whether it will blacklist the schools.
The government said last week that charter schools will be able to negotiate how many registered teachers they employ and how much they pay teachers. The government-funded schools will be another option for parents.
NZEI president Ian Leckie has concerns about unqualified teachers being employed by charter schools, but says the union will support its members if they work in the schools.
"Unqualified teachers certainly have no place in education," he told TVNZ's Q+A programme on Sunday, adding that qualified teachers will have to provide a "huge amount of support" to their unqualified colleagues.
Mr Leckie said the union was yet to consider whether it would blacklist charter schools.
"It's certainly divisive. Whether we would blacklist, I think you have to think carefully because the bottom line of anything that happens in education is children.
"Where we're totally opposed is putting unregistered teachers in front of children."
Charter Schools Working Group Catherine Isaac said many qualified teachers would be interested in working in the schools, and it was unlikely they would end up with a high number of unregistered teachers.
It was not clear whether teachers in core academic roles would be qualified, with Ms Isaac saying only that they would be "top-quality teachers".
Ms Isaac added that if someone like former SAS soldier Willie Apiata or former All Black Tana Umaga wanted to run a school's outdoor pursuits academy, they were unlikely to be turned down.
Legislation will be introduced to parliament this year to facilitate the schools and formal requests for proposals from potential sponsors will be called for once the legislation is passed.
All sponsors will be expected to open their schools for the beginning of the 2014 school year.