Children as young as 5 could come to New Zealand to study for up to three months each year on a visitor's permit, under immigration policy changes taking effect today.

Immigration NZ has announced several amendments to policy, including one that would enable visitor's permit holders in Years 1-13, which the agency says is usually between 5 and 18 years, to study for a single period of up to three months per calendar year in non-consecutive school terms.

Department head Nigel Bickle said these children could also come to New Zealand without their parents or legal guardians because the policy had no guardian requirements.

But while immigration rules allow 5-year-olds to study here without their parents, Ministry of Education rules prevent them from being enrolled.

The Ministry of Education's Code of Practice for the Pastoral Care of International Students restricts any signatories from enrolling anyone under the age of 10, and under the revised immigration rules, all students wanting to study longer than two weeks will need to be enrolled in schools which have signed the code.

Ministry spokesman Joss Debreceny said that, under the code, students under the age of 13 must live with their parent or legal guardian while studying here.

The code had undergone a revision, and now schools could enrol young international students between 10 and 13 as group students if they came to New Zealand without their parents.

The ministry has also published on its website a set of guidelines for schools hosting short-term international students.

"If a school-age visitor is not accompanied by a parent or legal guardian, schools should request a letter of consent from the visitor's parent or guardian, giving permission for the visit and approving the arrangements," the guidelines say.

Students under 10 still cannot be enrolled, even as group students.

"If a group of students come for a short, properly organised visit, then they may come without their parents or guardians if the students had their parents' or guardians' permission," Mr Debreceny said.

The ministry guidelines said schools should also ensure these students had "first language support" if they had limited English language abilities.

People involved with the export education industry said the policy change was positive and believed it would benefit the industry.

Josie Kim, a Korean education agent, said it would "most definitely" boost the number of young children coming from South Korea - New Zealand's biggest market for international students aged 13 and under.

"The changes will make New Zealand far more cost competitive for us to market now."

In the past, parents had to factor in the cost of also coming here, she said. Short English language or immersion courses were very popular.

In other changes taking effect today, all temporary permit holders will be able to study more than one course for up to three months instead of a single course under current rules.

(Source Lincoln Tan, NZ Herald)