Almost two thirds of Australian households have signed up to a national Do Not Call Registry to prevent telemarketers from contacting them.
Since the Australian Communications and Media Authority's (ACMA) Do Not Call Register began in 2007, eight million telephone and fax numbers have registered with the free service.
"This shows just how much Australians have embraced the register to avoid telemarketers' unsolicited phone, mobile and fax calls," ACMA chairman Chris Chapman said on Tuesday.
The Authority says nearly 90 per cent of those who signed up to the Do Not Call list noticed a significant reduction in unwanted cold calls.
Since 2007, more than 5.4 billion numbers have been checked against the register by the 6725 telemarketers and 193 fax marketers who have established accounts to vet numbers.
Once registered, numbers remain on the Do Not Call on the list for six years.
"ACMA is committed to ensuring businesses comply with Australia's telemarketing laws," Mr Chapman said in a statement.