With regard to the legality of not accepting cash - I looked it up, the
'legal tender' laws are often misunderstood. They only apply for the
'settlement of debts when no payment method was specified'. There is a
little bit on the RBA's website and I found other references too.
As long as the 'contract' which can be a sign saying 'card payments only',
is clear before goods change hands and thus a 'debt' incurred, the seller
can specify any reasonable method of discharging that debt.
If a business wants to be card only, that is perfectly legal, and a
'business decision' for that business.
There is a coffee and muffin cart on Redfern station that has NEVER
accepted cash. In large letters stuck to the back of their coffee machine
is 'card only'. That business has made the decision that the loss of
cash-only customers is offset by the efficiency (and lower risk of robbery)
of not handling cash (which would need a float, have to be reconciled every
The practice of adding the card handling fee to the price at card
presentation instead of just folding that transaction cost into the cost of
the goods is a bit rude, but the appropriate regulators allow the practice.
I gather regulators hoped to shame the banks into treating small businesses
better by making it obvious what they were charging these businesses, but I
don't think banks can be shamed.
I haven't used my actual Opal card for approx 2 years now. I've been paying
using my phone's 'card emulator' directly out of a debit account. The only
'downside' I can see is the Opal terminal cant show you the cost of the
trip immediately as it does when you 'tap out' with an Opal card. You have
to wait for the transaction to upload and show online before you can check
if the fare was correct. But it usually is.
Opal has not implemented pensioner/concession/child fares on 'contactless',
those users still need their 'special' opal cards and arrange for them to
be in credit before use.
I gather Queensland is finally updating Go Card to accept contactless bank
cards too. If Melbourne makes the transition too, the majority of PT trips
in the country will not need a specific operator card or ticket for fares.