The system was developed by Kamco (Keane Australia Micropayment Consortium) and is used by Public Transport Victoria.

The initial 10-year contract was worth approximately A$1.5 billion,[2] described by The Age as "the [world's] biggest for a smartcard ticketing system".

On 15 May 2023, the Victorian government announced it had signed a contract with Conduent, an American company, that will take over the Myki system for the next 15 years.

A "Myki Explorer" pack is available, intended for use by interstate and overseas visitors (or an option for users from outside metropolitan Melbourne).

The Myki system calculates the cheapest fare for a passenger based on the time and zone(s) travelled in on a given day.

This system still operates on V/Line services that run outside of the commuter belt area and where reserved seating is required.

[25] On 12 July 2005, the Kamco consortium was awarded the $494 million contract to develop the system, with the completion date being 2007.

[28] In February 2008, Public Transport Minister, Lynne Kosky, announced that the full roll-out of the system would not begin until the end of the year.

[31] The first field trial of the new Myki system was held on the Geelong bus network in late 2007, which identified problems.

[40] Myki became valid for travel on all metropolitan train services, but not trams and buses, from 29 December 2009,[41][42] though the system of purchasing cards was still cumbersome.

The limited remaining range of Metcards could only be purchased from staff at premium stations, from bus drivers, or from a PTV Hub.

The sale of Metcards at Premium (staffed) Metro railway stations was progressively phased out, and ceased entirely during October.

[45] On 29 December 2012, Metcard was switched off, and Myki became the only form of ticket valid on Melbourne public transport.

It was intended that the Skybus Melbourne Airport shuttle bus service (with its own, premium fares) would also accept Myki once the system was fully operational, but this did not happen.

Paper tickets remain for travel outside the Myki zone, such as to Warrnambool, Bairnsdale, Swan Hill, Shepparton or Albury.

A 30% discount for off-peak travel ran from 31 January to 24 August 2021 (defined as trips made between 9:30am and 4pm or after 7pm on weekdays).

The stated aim was to decrease overcrowding on public transport vehicles by encouraging people to travel during less busy times of the day wherever possible.

[53] Vouchers were released for one day of free public transport travel to encourage more people to visit the central city area.

[54] The facility to 'pause' or receive a refund of myki passes previously purchased was made available for periods of lockdown where most travel was banned.

[56] In the 18-month tender process, Conduent was chosen as the preferred operator over NTT data and Cubic due to the calls to have a change and Cubic's preference of installing their own ticketing machines, rather than utilising the current Vix Technology card readers and other infrastructure.

[58] Trials will commence in 2024, where new features will be added progressively but at the same time not rushed in order to prevent the heavily criticised initial introduction filled with technical problems in 2008.