iiNet has forked over $204,000 after the Australian Competition and Consumer Commission took exception to one of the Internet service provider's advertising campaigns.
The ACCC served the ISP with infringement notices because the company had failed to prominently state the total minimum price of its Naked Broadband 250GB Plan, a statement from the corporate watchdog said.
Although the ads, which appeared in Melbourne in November, stated the minimum total price, the ACCC believed it was not prominently displayed.
The ads contravened the Australian Consumer Law, the ACCC said.
"Consumers must be able to understand the true cost of an advertised product so that they can make informed purchasing decisions," ACCC chairperson Rod Sims said.
"Businesses must ensure that when they advertise part of the price of a good or service, the total minimum price is also prominently displayed."
An iiNet said the ISP was "surprised and does not agree with the infringement notices".
"We have strived to meet the equal prominence test but given there is no clear definition of that test, ISPs are finding it hard to avoid being fined nowadays," the spokesperson said.
"iiNet has paid the fine despite being disappointed that these matters can’t be worked through between the ACCC and the industry without formal enforcement measures being taken."
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In 2013 the ACCC finally resolved a long-running court battle with ISP TPG over the company's advertising campaigns.
In that case, the ACCC took action against the ISP because it had not included in its advertisements all of the costs related to its Unlimited ADSL2+ broadband plan.
The conflict was finally resolved in the ACCC's favour in the High Court of Australia, with the court reinstating a $2 million penalty against the ISP.
iiNet has been approached for comment.