In 1881 the first Adoption Act was passed and provided for the legal adoption of a child under the age of 15 years. This was increased to 21 years in 1939. A magistrate made an adoption order for Europeans and by the judge in the Maori Land Court for Maori people. From 1881 - 1915, access to the original birth entry was not restricted and the entry remained the official source of information for issuing a birth certificate to an adoptee. In 1940 all pre 1916 adoption records were transferred to the Central Registry in Wellington
From 1915 changes to legislation provided for the re-registering of the adoptee's birth under their new adoptive name.
In 1924 further restrictions were placed on obtaining certified copies of the adoptees original birth certificate.
From 1955 no personal inspection of an original entry for an adopted person has been permitted.
The Adult Adoption Information Act 1985 allows a person who is adopted and who has reached 20 years of age access to their original birth record under Section 4 of the Act.
The original certificate will provide date and place of birth, sex and original names. In some instances the certificate will have details on both the birth parents. If details of the birth parents are not recorded they may never have been registered in the first place or a veto has been placed by the birth parents. Sometimes the person placing the veto has left a letter of explanation, and request to the registrar should ask for this information plus any other non-identifying information that they may have.
Another source to check if you are unsure as to birth origins is police gazettes of mothers seeking maintenance from the alleged fathers of their illegitimate children - children both born and yet-to-be-born. Note for the years 1877 - 1925 there were a total of 1800 unmarried mothers with some 2000 babies involved, over 80% of who would have been born between the years 1900 - 1925.
The New Zealand Police Gazettes date from 1877, soon after central government took over policing. The volumes date from 1877 to 1990 when the gazette ceased publication. Access is allowed only to gazettes that are more than 100 years old. Each volume is indexed