The state's transport agency considered charging $10 for new Opal cards under plans to get most people using credit cards and mobile devices to pay for trips, leaked documents show.

The confidential strategy documents detailing the rollout of so-called contactless technology, obtained by the Herald and the ABC, reveal it was partly aimed at cutting the cost to the state of ticketing and stemming fare evasion, especially on trains to Sydney Airport.

Each Opal card costs the state more than $2 to produce and distribute. Credit:James Alcock

But Transport Minister Andrew Constance said there were “no plans to introduce any fee for new Opal cards”, and Opal was “here to stay” as the foundation of the state's public transport system.

“Contactless payments are available as a convenience to customers but it is still an Opal system and always will be,” he said, describing the leaked documents as outdated.