Legislation enacting the Government's latest round of welfare changes has passed its third and final reading in Parliament.
The Social Security Amendment Bill passed by 61 votes to 59, with the support of National, ACT and United Future.
Once the changes come into force on 15 July, beneficiaries risk having their payments halved unless their children fulfil core health and education requirements.
There are sanctions for beneficiaries with outstanding arrest warrants, for job-seekers who avoid drug tests and for work-tested beneficiaries who refuse offers of suitable employment without good reason.
It collapses seven existing categories into three main benefits for more than 320,000 people.
In light of continuing problems with the Novopay school payroll system, Social Development Minister Paula Bennett says she is keeping a close eye on the new benefit system's readiness.
Mrs Bennett says it is a massive IT undertaking that she wants to be seamless.