A new code of conduct for immigration advisers will take effect on Monday, as part of an effort to clamp down on dodgy operators.

The Immigration Advisers Authority last year warned prospective immigrants against using unregistered advisers, saying they can be incompetent and unethical, and said the new code will give immigrants peace of mind.

The Licensed Immigration Advisers Code of Conduct 2014 updates the 2010 code to provide greater clarification for advisers and consumers.

Under the code, advisers have to show evidence they are licensed and must act professionally and honestly.

Anyone providing New Zealand immigration advice onshore or offshore must be licensed by the authority, unless they are exempt. Exempt people include New Zealand lawyers.

The new code was developed by the Immigration Advisers Authority with input from 108 licensed immigration advisers, immigration industry bodies and migrant groups.