The Government of the Northern Territory, Australia has a Northern Territory Registry of Births, Deaths and Marriages. Online searches of current or historical NT vital records at this registry requires a fee.
For current birth, death, or marriage certificates visit the application site.
Northern Territory Birth, Marriage, & Death Records
“From 1863 to 1910, the NT was administered by the South Australian (SA) Government. Some Territory archives created by the SA Government are now held at the NTAS while some remain in SA.” See the SA Registry of Births, Deaths and Marriages options.