Telstra has said it is now blocking approximately 6.5 million suspected scam calls a month, at times up to 500,000 a day, thanks to automating the former manual process that sat at around 1 million monthly scam calls.
The system that Telstra built in-house forms the third leg of its Cleaner Pipes program.
In May, the company kicked off with DNS filtering to fight against botnets, trojans, and other types of malware, and extended to blocking phishing text messages purporting to be from myGov or Centrelink before they hit the phones of customers.
"Scam calls are not only annoying, they also have a real financial impact on Australians and are estimated to have cost ordinary Australians nearly AU$48 million last year," CEO Andy Penn wrote in a blog post.
"If you think you are receiving a scam call, our simple advice is: Hang up."
Penn said the company would only call customers between 9am to 8pm on weekdays, and 10am to 3pm on Saturdays, and never on a Sunday.
"The exception to this is if you have an unpaid account or a customer-initiated inquiry with respect to an order, fault or complaint, someone from Telstra may call you outside of these hours," he added. "We'll respect your wishes and terminate the call if you say no thanks and we won't call repeatedly if you don't answer -- these are all hallmarks of scam calls."
The CEO said any customers that believe they have been scammed should contact the telco.
"We see a future where scam calls of this type are effectively ring-fenced and eliminated from our network," Penn said.
"It will take more investment and innovation, and continued support from government but we have an ambition to make these kinds of changes to continue to improve the level of trust that Australians have in their phones, their emails and the websites they visit, and to encourage the rapid expansion of our country's digital economy however we can."
Last week, Telstra reported a challenging first half of its fiscal year as it saw double-digit drops in revenue and earnings before interest, income tax expense, depreciation, and amortisation (EBITDA) and, consequently, it has revised its guidance downwards.
For the half year to December 31, the company saw revenue fall 10% to AU$12 billion, while EBITDA dropped 14.7% to AU$4 billion, and EBIT took a 20% hit to decline to AU$1.64 billion. Thanks to a substantially lower level of income tax, down 60% to AU$209 million, net profit fell only 2.2% to AU$1.13 billion.