A banner used on the Aussie Broadband home page from at least 30 January to 11 July.

Broadband provider Aussie Broadband has had to remove the words "congestion-free" from its advertising after the competition watchdog raised concerns about the use of these words with the company.

In a statement, the Australian Competition and Consumer Commission said Aussie Broadband had been making the claim that it offered "congestion-free NBN" and a "congestion-free network".

The words were used widely in ads on its website, Facebook posts, advertisements, targeted emails and direct mailouts.

The ACCC pointed out that congestion was experienced by Internet users when demand exceeded available capacity and this was most likely to occur during the peak hours of 7pm to 11pm.

“We were concerned that Aussie Broadband’s statements might lead consumers to believe that Aussie Broadband’s services would not ever experience congestion, when that was not the case,” ACCC chair Rod Sims said.

“Our own observations from the ACCC’s Measuring Broadband Australia program indicate that all broadband providers experience congestion from time to time, although the extent of congestion depends on how well networks are managed, and some are better than others.

“It’s important to note that Aussie Broadband recorded the fastest NBN download speeds in our most recent speed tests. However, all NBN providers should ensure that they do not use absolute statements like 'congestion-free' when promoting the speed and reliability of the broadband services they offer.”