At the end of the 1970 season, the winners of the Northern, Central, and Southern leagues - Mount Albert-Ponsonby (Auckland), Waterside (Wellington), and Caversham (Dunedin) respectively - took part in a play-off series to decide the two teams which would be granted entry to the national league.
As a result of therse matches, Mount Albert-Ponsonby and Caversham gained entry to the national league.