What is imputation credits?
Imputation credits regime was introduced in NZ in 1988. It is a system which avoids double taxation on already taxed income. So, when NZ Company issue you a dividend this is reported in your tax return as income, and imputation credits attached with that dividend are used as tax credits to avoid double taxation.
Section LA5 (4) ITA 2007: permits imputation credits to be used as credits to settle one's income tax liability.
What is franking credits?
Franking credits is similar to what we have in NZ as imputation credits. In Australia imputation credits are referred as franking credits.
NZ and Australia both have similar imputation credit tax regime which ensures the taxes paid in local jurisdiction are not paid twice.