An advantage of of these two systems is the very thin card used and production costs of around l5c per card.
Cases of fraud involving the sophisticated reprogramming of magnetic cards has occurred in more than one country.
The Anritsu and Tamura cards both give an indication of the approximate remaining credit to the user by means of a punched hole. On the Anritsu system the indicator scale is a standard length regardless of the value of the card.
So on a $2.00 card a hole will be punched for every 30c call made, ie., a maximum of 7 holes. However, on a $20.00 card ($21.00 credit) there is insufficient room to punch a possible 70 holes so the card only gets punched a maximum of 11 times as the remaining credit value decreases.
There goes the theory that it was a free call because it didn't punch the card.
On the Tamura cards the use indicator is longer on a card with a greater number of units, although this appears to be a logarithmic extension.
The much flouted theory that blocking the punched holes allows the reuse, or extension of credit, is total nonsense because the card reader
is reading magnetic information, not holes. The holes are merely punched as a consumer friendly gesture.
With Autelca system by a Swiss company, the the information is stored on the visible magnetic strip like the Hong Kong card on the right. In this card it is necessary to insert the card in a phone to determine any remaining credit.
The card on the left from Eastern Telecom Philippines comes from GPT of the United Kingdom. It has a use indicator which has a dent punched in the card as it is used, whereas others, like the New Zealand card, has no use indicator and again it is necessary to insert the card into a phone to determine the credit.
The card on the right is from Italy and uses what is commonly referred to as an Urmet system, but can be made by at least 3 different companies.
Before using these cards, you are required to tear of the perforated corner. Unless this is done, the card will not be able to be inserted far enough into the phone to allow operation. These cards, as with a few others, have an expiry date after which the card becomes invalid.
Since the inception of phonecard systems, many different companies have developed their own systems and some countries have chosen to go their own way rather than use existing developments and create another system unique to their own country
This has been the system with the greatest number of variants. The basic principle being that the information is stored on the card in the form of a magnetic field, the place of storage being unseen on some such as the Anritsu system used in Australia and the Tamura system used in Japan 
