Immigration advisers will have to be licensed under legislation passed by Parliament last night.
If they operate without a licence, they will face a fine of up to $100,000 and/or seven years in jail.
Immigration Minister David Cunliffe said the days of "shady immigration agents ripping off unsuspecting migrants with impunity" were over.
"Migrants, their communities and the 90 per cent of immigration advisers who are reputable will welcome this legislation," he said.
"The call for the regulation of immigration advisers came from migrants."
Mr Cunliffe said migrants had been ripped off, told lies, had money and documents stolen and had been let down.
"These shonky operators also provide fraudulent documentation to immigration officials – often knowingly," he said.
"Now they can either get out of business or face the consequences."
The Immigration Advisers Bill also sets up an Immigration Advisers Authority within the Department of Labour and an Immigration Advisers Complaints and Disciplinary Tribunal within the Ministry of Justice.
To hold a licence, advisers have to meet competency standards and be "fit to practise". That includes consideration of any previous convictions.
Immigration agents and advisers will have two years to get their licences, and after that immigration officials will not accept applications from unlicensed people.
Offshore advisers will also have to be licensed. They have three years to comply.
The bill passed its third reading without dissent.