Section 120 of the Trade Marks Act 1995 (Cth) (TMA) is the infringement provision. Have a look at it here.
There are three elements to trade mark infringement.
First, use of a sign “as a trade mark“. That means the sign must be used as a “badge of origin” or, put another way, it must indicate the trade source of the goods. Uses which are descriptive of the goods or services in some way are generally not considered to be use “as a trade mark“. There is a fuller discussion of the meaning of “as a trade mark” here.
Secondly, the sign used must be at least “deceptively similar” to the registered trade mark it is said to infringe. The phrase “deceptively similar” is defined in s 10 of the TMA. See here for more detail.
Thirdly, the sign must be used in relation to the goods or services for which the registered trade mark is registered (s 120(1)) – or goods or services which are “of the same description” or “closely related” to the registered goods or services (s 120(2)). For a discussion of what these phrases mean, see here.
Note that under s 120(2), otherwise infringing use will not infringe if the defendant (respondent) establishes that using the sign as he or she did “is not likely to deceive or cause confusion“. How a Court could find that a mark is deceptively similar to another mark but its use is not likely to deceive or cause confusion is unclear – it’s not just you.
There is also the rarely used s 120(3) TMA. It provides that infringement will occur when a registered mark is “well known in Australia” and another, deceptively similar mark is used as a trade mark in relation to “unrelated” goods or services if such use would indicate a connection between the unrelated goods or services and the registered owner and the interests of the registered owner are likely to be “adversely affected.”
There are some statutory defences to infringement provided in the TMA. See here.
The relief available for trade mark infringement is set out in s 126 of the TMA. More here.