I am advised:
Transport for NSW has already installed over 350 Opal top up machines across
the Opal network, at locations covering 99 per cent of customer trips. A list
of top up and single ticket machine locations is available via the Opal
The preferred method of topping up by customers is via the more than 2,200
Opal retailers. These retailers are located across metropolitan Sydney and
Transport for NSW has also invested in accessible digital channels such as
the Opal Travel App, for customers to Top Up on the go wherever they are.