Transport Minister Gladys Berejiklian said the machines would be rolled out to train stations, ferry wharves and light rail stops next year.

The testing phase starts this week with the first machines due to appear on stations in western Sydney and the CBD early next year.

Almost 350 machines will be rolled out over the next 12 months, providing coverage for about 99 per cent of customers.

Mrs Berejiklian said it was not known exactly when Illawarra stations would get the machines.

"We are still finalising the top-up machine roll-out plan but obviously, will give priority to areas where there is the greatest need," Mrs Berejiklian said.

There will be three different types of machine brought in.

The first 100 machines will allow customers to top up their Opal card with a debit or credit card, the second type will include disposable tickets — which are distinct from existing paper tickets — and the third will also accept cash.

It is not known which machines will appear in the Illawarra but it is understood none of the machines will dispense Opal cards.

Meanwhile, several new apps include Opal fare calculators to estimate trip costs.

The Transport Info website also shows Opal fare estimates when customers plan their trip.

The free fare calculator apps - Opal Travel and Opal Fares - can be downloaded via the iTunes app store or Google Play marketplaces.

The new trip planner with fare estimations is available at the revamped transportnsw.info.