An overview of Australian Dining Etiquette
There is no great tradition for business entertaining in Australia and it certainly shouldn't be viewed as the quick way to cement relationships with a new client or contact. In fact, you are more likely to be asked out for lunch or dinner once a firm relationship has been established - in this way the meal can in no way be seen to have influenced a business decision.
People will very often 'go Dutch' over a meal - this means that the bill is split equally amongst those present at the meal. If you wish to pay, make sure you make this clear before the meal to avoid any embarrassing debates when the bill is presented.
A very important local etiquette is that if invited to a pub or bar for a drink, it is very important to make sure you pay your 'shout' - that means that everybody is expected to pay for a round of drinks. It is unadvisable to develop a reputation as someone who does not pay for his or her fair share of the drinks!
Tipping is not always necessary but is usually expected at the better restaurants. (If in doubt ask your Australian counterpart what the etiquette is.) Tips are usually for about 10% of the total bill.