The first 'Air Mail' stamp was issued on 10 November 1931 even though there was no regular airmail service at the time.
These stamps showed a typical New Zealand scene with an aeroplane flying over a lake. A further stamp was soon overprinted with the words FIVE PENCE to raise the value of the stamp to use on special Christmas airmail flights. Then, to mark the first official airmail flight from New Zealand to Australia on 17 February 1934, another stamp was overprinted TRANS-TASMAN AIR MAIL "FAITH IN AUSTRALIA". The Post Office stopped issuing air mail stamps at the end of 1939.
'Express Delivery' stamps were issued on 9 February 1903. 'Express Delivery' was a service where payment of a special fee would mean that your letter would be specially delivered as soon as possible. The same stamp was used for 36 years until, on 16 August 1939, a new design showing a speeding car went on sale. Because of World War II, the 'Express Delivery' service was stopped from December 1941 but the stamps stayed on sale until 30 June 1948.
'Postage Due' stamps were issued on 1 December 1899 to put on letters that had been posted without the correct postage on them. The design of the 1899 'Postage Due' stamps was a fancy green frame with the value of the stamp inside the frame in large red figures. This design was changed and new stamps issued in 1902 because the 1899 issue had been printed in a hurry and wasn't of very good quality. The New Zealand Post Office stopped issuing 'Postage Due' stamps on 30 September 1951.