Stamp Vending machines were first tested by the Postmaster-General's Department as early as 1903. No progress was made due to the different sizes of stamps then in use printed by the various former colonies.

A coin-in-the-slot impressing machine was designed by a Mr W. Hollingsworth was trialled at the Brisbane GPO during 1903 but was withdrawn by its owner after it developed faults. It was given a further trial in Dunedin (NZ) but then disappeared from view.

In June 1905 the world's first stamp vending machine was trialled in Wellington, New Zealand. This event was celebrated by NZ Post with the release of a Centenary of Vending Machines envelope in 2005.

Another stamp selling machine developed in New Zealand by Messrs Dickie and Brown was obtained for evaluation. To assist in the evaluation, the PMG made available 500 sheets (120 on) of the current Victorian 1d postage stamp. These were first overprinted by the Stamp Printing Branch in Melbourne with two heavy black bars across each stamp.

The machine was installed for public trial at the GPO Melbourne from March 9th to 14th, 1908. Rolls of the current Victorian stamps were specially made up for the machines.

The test was satisfactory but it was decided that the introduction of stamp selling machines should be deferred until uniform sized stamps were introduced to permit the use of standard machines in all States.

Between 1900 and 1909, some early trials were conducted in Australia with the Pitney - Bowes franking machine which apparently involved its official use as it was not authorised for private use until 1927.

With the introduction in 1913 of the uniform stamp series, it was possible to have manufactured in July 1913 standard coils of 960 of the ½d and 1d Kangaroo and Map stamps. The coils were made available for use in stamp affixing machines then in common use in Post Offices. Licensed stamp sellers also made up privately coils for use by customers with stamp affixing machines. Some coils of various other lengths were also manufactured. The manufacture of the ½d coils was discontinued in October 1916 due to the low demand but was resumed in 1918 when the ½d war tax increased postage to 1½d. The ½d coils were again discontinued in late 1920.

Late in 1913, the Department arranged tests of three different types of vending machines.

A large machine, made by the British Electric Machines Ltd, was attached to a letterbox in front of the Melbourne Town Hall on December 11, 1913 and dispensed 1d Kangaroo & Map stamps.

The ½d stamps were dispensed from the two other machines installed at the counters of the GPO Melbourne and the Stock Exchange PO, Melbourne. Both machine types were soon discontinued.

In 1914, two other vending machines were attached to letter receivers in Melbourne. One was installed at the corner of Collins and Elizabeth Streets from February 1914 to July 1918. The other was in Flinders Street from September 1914 until October 1918. It is assumed that they dispensed 1d stamps as that was the current rate for letter postage. Their removal may have also been linked to the new postage rate of 1½d and the possible inability of the machines to be modified.

Another type of stamp vending machine was invented by Mr H Adamson of Stanmore, NSW. It was tried in Sydney from October 6 1915 to February 9 1916 affixed to a telegraph pole in Pitt Street and dispensed 1d stamps. From July 24 to November 22 1918, it was in use at the Sydney GPO.

Demand for coils of stamps gradually lessened until in April 1920 it was announced that "postage stamps in coils or rolls may be purchased at post offices where the demand justifies the supply". This note continued to be published in the Post Office Guide until 1927.

Records show by 1920, coils were available in ½d, 1d and 1½d values. In September 1920, the values were also available punctured "OS". The 1d and 2d orange King George V sideface stamps were made in coils from late 1920. Coils of other values were possibly made up from time to meet specific needs. With the increase in the general postage rate in 1923 a 1½d coil was introduce together with the reintroduction of the ½d coil.

In 1928, ten Australian-made stamp vending machines were purchased from Brown Inventions Co. and placed in service on July 18. The locations (presumably all at Post Offices) were:

     GPO Melbourne (Spencer Street)    Elizabeth St

     Brighton                                               Brunswick

     Footscray                                            Hawthorn

     Northcote                                            North Melbourne

     Prahran                                               South Melbourne

Each machine delivered a 1½d stamp from a coil of 960 upon insertion of a penny and a halfpenny coin. With the rate change in 1930, the machines were modified to 2d operation as from August 4 1930. It is thought that at least one machine had been removed from service prior to this as a 1½d machine exists in the Australia Post collection.

The machines had some unsatisfactory aspects in their operation. The stamp joins were often poor and the machines suffered due to bent coins and foreign matter being inserted in the coin slots.

In August 1937, the Australian Post Office let a contract for 500 coil vending machines at a cost of £12 each to Hall Telephone Accessories Ltd (later taken over by Associated Automation Ltd) who also were supplying coil machines to the British Post Office. This was preceded by tests of Australian coils in the Hall machine. Generally known as the B4 machine, eventually 3000 were purchased and saw general use throughout Australia over the next four decades.

Though limited to a single coin type, it could be set to dispense a stamp after the insertion of one, two or three coins of the one denomination. The machine was robust and reliable with the energy needed to drive the delivery mechanism being provided, indirectly, by the user inserting the coin/s.