Having decided on the GPT system of cards and cardphones, Telecom New Zealand began trialing the system in early May 1989, inside two military installations near Christchurch.
Five cards with deep notch, with values of $2, $5, $10, $20 and $50, were produced especially for the trial, and each card had the same design showing a colour photograph of the Chief Post Office in Christchurch.
As all the cards that were not sold, or used by technicians, were officially destroyed, the quantities really distributed were as follows: $2 (11,021), $5 (7,254), $10 (5,775), $20 (2,576), $50 (863).
