When Letter Telegrams were introduced on 1 January 1914, the rates were set at 6d for 10 words (town and suburban) and 9d for 10 words (intra-state). The facility was intended for use by individuals sending messages of a personal or private nature. It was not to be used for commercial purposes.
On 19 December 1918, an amendment to the Post and Telegraph regulations was issued to provide that letter telegrams was to be confined to messages of a social, domestic or private nature as distinct from those which are of a commercial or official character.
The regulations governing the use of Lettergrams were included in the 1922 Post & Telegraph Guide. Within two years however, such progress had been made, through the public's use of the system together with the uptake of the telephone system, that new regulations were introduced in 1924. These amendments provided that the lettergram system would apply to all classes of messages, including commercial and official. It also enabled people to hand in lettergrams at telegraph offices which were open after 7 p.m. subject to delivery by post at lettergram offices of destination.
The amended regulations, which took efect from 1 February 1924, were as follows:
372a. (1) Letter telegrams, in this regulation referred to as lettergrams, shall be accepted for transmission within the Commonwealth, subject to the conditions contained in this regulation.
(2) Lettergrams will be accepted at any hour at telegraph offices which are open after 7 p.m. subject to the condition that delivery is effected by posting at the lettergram office of destination. Lettergrams will be delivered as ordinary letters by the first delivery on the day following that on which the lettergram is handed in. They may also be accepted for transmission by telegraph to a lettergram office for further despatch by mail within or beyond the Commonwealth. If lettergrams are intended to be forwarded by post beyond the Commonwealth, payment of the postage charges most be made by the sender. From the moment the lettergram is posted at the lettergram office of destination, it shall be regarded and handled as a letter.
(3) Lettergrams must be written in the English language, must have a connected meaning and must bear the word "Lettergram" before the address; such word to be counted.
(4) Lettergrams shall not be transmitted as "multiple" telegrams, nor shall registered addresses be used in lettergrams.
(5) In all other respects the form and manner in which lettergrams are written must be in accordance with the regulations dealing with ordinary telegrams.
(6) The address should be set out as indicated in the following typical example:
Lettergram - John Watson, 17 Bourke Street, Ararat.
(7) Subscribers to a telephone exchange at which service is given between the hours of 7 p.m. and midnight may transmit a lettergram during those hours by telephone to the nearest telegraph office which is open for lettergram business, where they will be treated similarly to lettergrams handed in at that office. In such cases the subscriber shall be required to pay, in addition the charge for transmission, a telephoning fee of 3d. for each 40 words or portion thereof.
(8) There shall be charged in respect of lettergrams which are to be transmitted over the trunk line system to or from offices where trunk line faculties are available after 7 p.m., in addition to the charge for transmission and the telephoning fee specified in the last preceding sub-regulation, the charge for the use of the trunk line as provided by the telephone regulations.