From August Transport for NSW is rolling out the ability for commuters to use contactless payment options on the state's buses.

Rather than give their credit card to the driver, people will simply tap on with it - the same as with an Opal card.

Mobile wallets on smartphones and tablets connected with a credit card will also work, as will wearable devices.

"Launching this technology on buses marks the final piece in the contactless payments puzzle and we expect all buses on the Opal network to be able to accept credit and debit cards by the end of September," Transport Minister Andrew Constance said.

In the Illawarra that means people catching Dion's and Premier Illawarra buses can reach for their credit card rather than an Opal card.

The contactless payment option will charge the user a full Adult fare, meaning it would not be open to those holding a child, concession or seniors Opal card.

The weekly travel reward, the transfer discount and off-peak pricing will also apply the contactless payment option.

Commuters catching a train on the South Coast line have been able to pay via credit card since late last year.

"Launching this technology on buses marks the final piece in the contactless payments puzzle and we expect all buses on the Opal network to be able to accept credit and debit cards by the end of September," Mr Constance said.

The minister said the contactless payment option was an enhancement of the existing Opal system rather than something aimed at replacing it.

"Opal remains the foundation for customers to access the transport network in a digital world and contactless transport payments are just another piece of our expansive Opal network," Mr Constance said.