Canada's big phone companies warned MPs on a parliamentary committee Tuesday their networks aren't yet ready to implement new anti-spoofing technology to guard against fake calls — and many existing landline phones and cellphones will need to be upgraded in order for the technology to be effective.

Representatives from Bell, Rogers and Telus appeared Tuesday before the Industry, Science and Technology House of Commons Committee that's studying how to prevent the millions of fraudulent phone calls Canadians receive each month.

The telecommunications companies, known collectively as the Big 3, told parliamentarians they are not fully ready to implement technology that alerts customers when a caller is disguising their phone number. Many Canadians have been duped by scammers who use phone call display information to seem like they are calling from a government office or a bank.

The CRTC has given companies until Sept. 30 to adopt technology known as STIR/SHAKEN (Secure Telephone Identity Revisited/Signature-based Handling of Asserted Information Using Tokens). With the help of a checkmark or audible sound chime, for example, STIR/SHAKEN could alert a person if a call is genuinely from a verified number.

Jonathan Daniels, Bell's vice president of regulatory law, said the company supports the rollout of this new technology. Still, Daniels said unleashing it this early is of little benefit in the fight against fraudulent calls. That's because Bell's legacy circuit equipment isn't ready to utilize STIR/ SHAKEN entirely, and many landlines and smartphones themselves aren't capable of displaying whether a number is coming from a legitimate source.

"We're still planning on launching it in September," Daniels said. "If you turned on STIR/ SHAKEN tomorrow or today on our network, very very few people would actually have phones that can actually benefit from it."

"It is for this reason that we and most of the telcom operators propose that the CRTC STIR/ SHAKEN mandate be delayed until we get the rules of the regime figured out."

Daniels said Bell would like to see the deadline pushed to June 2022.

Jérôme Birot, of Telus, told MPs that initially STIR/SHAKEN will only stop fraudulent calls that originate in Canada and the U.S because few other countries have adopted the technology.

"However, many fraudulent calls originate from outside Canada," Birot, Telus' vice-president of voice and services development operations, said.

Marketplace was present earlier this week during the arrests of two Canadians linked to the CRA phone scam. 3:13

CRTC open to extending the deadline

CRTC Chairperson Ian Scott told MPs the commission recognizes there have been issues getting the new system up and running in the U.S and Canada and left the door open to extending the deadline.

"We have to be open, and we have to understand that there may be technical challenges," Scott said. "If there are (the Big 3), they'll present them to us, and we'll only, if necessary, add additional time."

The countdown to adopting STIR/ SHAKEN comes as Canadians increasingly are being bombarded with nuisance and often fraudulent phone calls.

Scott told the committee Tuesday since the CRTC created the Do Not Call List in 2008, 14 million numbers have been added, and in 2019 about 858 numbers were added daily.

Watch the full Marketplace episode on phone scams and spoofing, To Catch a Scammer below: