Most interestingly, the rates of postage for just about everything were uniform except for the crucial revenue earner of local intrastate. The Colonies had negotiated as a collective, in 1881 with the U.P.U, and prior to that, Britain, for uniform foreign postage. At the time of federation all States had a foreign letter rate of 2½d per ½oz and foreign postcard of 1½d. Similarly, all states had negotiated amongst themselves during inter colonial conferences for uniform interstate rates. 2d (per ½oz) for letters, and 1d for postcards.
Most States (NSW, QLD, WA & TAS) operated a common two tier intrastate rate. 1d within city limits, 2d within the state. South Australia had a flat 2d rate, while Victoria had 1d on all mail (as of April 1901). All this disparity was done away with dramatically on 1st May 1911 (at the end of the book keeping clause), to a flat rate of 1d to anywhere in the British Empire. Not just anywhere in Australia, anywhere in the Empire!
Not all was stagnant during this time. Significantly, those rates which were uniform to begin with were manipulated as circumstances dictated. The rate to the UK was reduced in 1905. The Commonwealth could do so because no state could cry unfair advantage. Newspapers were one area where there was no opposition to uniformity since all states subsidised them to varying degrees, all benefited by any increase (or reduction in subsidy). Some colonies had previously carried newspapers for free. In 1902 (as early as practicable) newspaper rates for all states were set at ½d per 10oz.
However, the following table shows an intriguing situation.
According to this table then, one small hamlet nestled in an old volcano with a population of 5 sheep and an alligator, prevented a uniform postage series from occurring. The excuse beggars belief. Had uniformity occurred, the increased revenue in the huge state of Victoria would have subsidised any losses in Adelaide, without Melbourne even noticing it was doing so.
There was some mild justification in the other book keeping excuse. The PMG, James Drake, was scared witless by Tasmania, who claimed they would lose more than £10,000 annually from Tattersalls if uniform postage occurred, due to self addressed envelopes. A claim later disproved in parliament. However, recurring fears of this ilk, kept successive PMGs at bay. Specifically, all states maintained separate administrations for convenience in accounting. Regardless, this should not have prevented either uniformity, nor common postage. The real reason was much more mundane. Total incompetence, as discovered by a Royal Commission into this very problem.