Back in August, signing for credit cards was phased out in favour of making people use a PIN instead. While there was an adjustment period to allow smaller businesses to update their terminals if needed, from Monday (20 October) signing for your credit card will be all but dead in Australia.
Credit card picture from Shutterstock
The only exceptions will be overseas cards that don't have a PIN associated with them, or customers who are unable to easily type or memorise numbers (for whom special arrangements can be made by their bank). For everyone else, it's PIN time -- so if you've missed all the previous warnings, get onto your bank quickly to arrange one.
The one context where you won't need a PIN either is if you use a payWave or PayPass card for a sub-$100 transaction. Those should go through automatically.