The style 'The Right Honourable' is accorded when a Senator or Member is appointed a member of the Privy Council, an appointment and title retained for life.
The style 'The Honourable' is accorded to:
Position President of the Senate
Envelope Senator the Honourable John Smith
Salutation Dear Mr President
Position Speaker of the House of Representatives
Envelope The Honourable John Smith, MP
Speaker of the House of Representatives
Salutation Dear Mr Speaker
Position Prime Minister
Envelope The [Right] Honourable John Smith, MP
Prime Minister
Salutation Dear Prime Minister
Position Minister (Senate)
Envelope Senator the [Right] Honourable John Smith
Minister for ...
Salutation Dear Minister
Position Minister (House of Representatives)
Envelope The [Right] Honourable John Smith, MP
Minister for ...
Salutation Dear Minister
Position Senator
Envelope Senator (or Senator the [Right] Honourable John Smith
Salutation Dear Senator Smith
Position Member of the House of Representatives
Envelope Mr/Mrs (or the [Right] Honourable) John Smith, MP
Salutation Dear Mr / Mrs Smith
Position Premier
Envelope The Honourable John Smith, MLA, MP or MHA *
Premier of ...
Salutation Dear Premier
Position Minister (Legislative Council)
Envelope The Honourable John Smith, MLC
Minister for ...
Salutation Dear Minister
Position Minister (Legislative Assembly)
Envelope The Honourable John Smith, MLA, MP or MHA *
Minister for ...
Salutation Dear Minister
Position President of a Legislative Council
Envelope The Honourable John Smith, MLC
President of the Legislative Council
Salutation Dear Mr President
Position Speaker of a Legislative Assembly
Envelope The Honourable John Smith, MLA, MP or MHA *
Speaker of the Legislative Assembly
Salutation Dear Mr Speaker
Position Member of a Legislative Council
Envelope The Honourable John Smith, MLC
Salutation Dear Mr / Mrs Smith
Position Member of a Legislative Assembly
Envelope Mr / Mrs John Smith,MLA, MP or MHA *
Salutation Dear Mr / Mrs Smith
All letters are signed (conclusion) with Yours faithfully.
* MLA - Northern Territory, Queensland, Western Australia MP - Victoria, South Australia, New South Wales, Federal MHA - Tasmania, ACT