IELTS use for immigration purposes for New Zealand and Canada

New Zealand

New Zealand has used the IELTS test since 1995. Initially, level 5 scores in each of the four modules were required of the prospective applicants; those who could not achieve required scores could pay a NZ$20,000 fee instead, which would be fully or partially refunded later if the migrant were able to successfully take the test within a certain period (3 to 12 months) after his or her arrival to the country. A few years later, the policy was changed: the fee was reduced, and, instead of being potentially refundable, it became treated as a "pre-purchase" of post-arrival ESL tuition.
Presently, applicants desiring to achieve permanent residence in New Zealand via the "Entrepreneur Category" migration programme must prove a "reasonable" level of competence in English. Unless the applicant has studied and/or worked for a sufficiently long period in New Zealand or other English-speaking countries, this normally should be demonstrated by achieving the overall band of 6.5 on the IELTS.

Canada

Citizenship and Immigration Canada uses the results of IELTS and/or TEF as a conclusive evidence of one's ability to communicate in English and/or French. For the purposes of the skill-based immigration points test, one receives separate points based on his or her performance on each of the four modules (reading, writing, speaking, and listening) or IELTS; the score of 4 on a particular IELTS module is sufficient to earn the maximum points for this particular capacity, except for the listening module, which requires the score of 8 to earn the maximum points.
The CELPIP (Canadian English Language Proficiency Index Program) test scores are mentioned by the Canadian immigration application forms as an alternative to IELTS.
Submitting one's IELTS scores is also one of the several ways to evidence one's proficiency in an official language when applying for Canadian citizenship.