October 29, 2025

CST-GA Renews Call Authentication Support With TransUnion for Canadians

Robocalls aren’t just a problem in the U.S. but also north of the border. Spam calls made up 18.3% of calls from unrecognized numbers in Canada in 2022, with 6.3% of them considered fraudulent.

In Canada, like in the States, the STIR/SHAKEN call authentication support system aims to combat call spoofing. Spoofing involves disguising a phone number to make it appear like a call is coming from a trusted source. Typically, these illegal robocalls will masquerade as law enforcement or a government agency.

Recently, the Canadian Secure Token Governance Authority (CST-GA), which oversees STIR/SHAKEN in Canada, extended its agreement with TransUnion to provide support for telecommunications service providers participating in the system.

CST-GA Renews TransUnion Partnership

As part of its commitment to reducing robocalls, Canada is currently participating in STIR/SHAKEN, which can prevent call spoofing by authenticating caller identities and ensuring incoming calls are genuine and not fraudulent. TransUnion will continue to serve as the Secure Telephone Identity Policy Administrator (STI-PA) for the system, a role that involves issuing and managing the digital certificates that telecom companies use to verify caller IDs.

What Is the CST-GA?

As the group overseeing the implementation of STIR/SHAKEN in Canada, the CST-GA coordinates with digital certification authorities and telecom companies such as Bell and Telus to maintain call authentication standards. It also ensures STIR/SHAKEN is doing what it should be to reduce call spoofing, which is a breach of Unsolicited Telecommunications Rules from the Canadian Radio-television and Telecommunications Commission (CRTC). Violations of these rules can lead to fines of up to $1,500 (CAD) for individuals and up to $15,000 for corporations.

The CST-GA became a mandate from the CRTC, the equivalent of the Federal Communications Commission (FCC) in the U.S., in 2019.

What Is a STI-PA?

A STI-PA like TransUnion supports the digital certification process for the STIR/SHAKEN system. As well as issuing and managing certificates for telecom companies, it ensures compliance with call spoofing standards, ensuring all calls are properly authenticated.

By reducing the problem of call spoofing, an STI-PA can, in practice, restore the integrity of legitimate businesses like yours that rely on outgoing calls for genuine reasons, such as contacting customers about new products and services. However, as you’ll find out later, this isn’t always the case.

Need for Call Authentication Support in Canada

Research from TransUnion reveals that 77% of Canadians prefer using the phone for urgent or complex matters; however, 72% have ignored legitimate calls because of safety concerns. Caller ID authentication methods like STIR/SHAKEN aim to rebuild trust in voice communications, enabling customers to answer the phone with confidence and not fear fraud.

“Canadians need stronger protection from impersonation scams and fraudulent calls,” says Regional President of TransUnion Canada Juan Sebastian D’Achiardi, as reported in a TransUnion press release. “We’re proud to continue our partnership with the CST-GA to deliver solutions that combine innovation and security.”

Steps for Protecting Business Calls

True call authentication is necessary to protect Canadian consumers. However, businesses like yours may be impacted by recent efforts—for instance, if STIR/SHAKEN can’t verify your numbers correctly, leading to flags and blocks. Here are some ways to protect your business calls:

Abide by Call Compliance

Dialing people on Canada’s National Do Not Call List (DNCL) or calling customers outside of business hours can harm your call reputation, so play by the rules and ensure call compliance at all times.

Engage in Proper Dialing Ethics

Practicing good data hygiene, maintaining outbound calling compliance standards, and adhering to other ethical dialing practices can increase the reputation of your business and prevent calls from being flagged.

Remediate Phone Number Flags

If STIR/SHAKEN or other protocols flag your calls as spam, you need to resolve this issue. Start by identifying which carrier is flagging your calls and why, and then contact them to get these labels removed. Unfortunately, this may take some time, so you’ll want to act as quickly as possible. Additionally, our Number Redress & Remediation services can assist with this process.

Ongoing Reputation Monitoring

Improving your call reputation isn’t a one-time thing; it’s an ongoing task that requires your full attention. Remember, your numbers are the first thing customers see when you phone them. As such, you’ll want to proactively monitor your phone number reputation.

How Caller ID Reputation Can Help

The CST-GA recently announced it will continue its partnership with TransUnion to support Canadian telecom companies. This partnership aims to reduce call spoofing attempts by promoting the STIR/SHAKEN framework. However, this collaboration hasn’t always been successful. Some legitimate businesses are struggling to get their calls correctly authenticated, resulting in messages being flagged or banned.

With Caller ID Reputation, you can mitigate these problems by identifying flagged caller IDs and mitigating future flags. The result? More of your calls get through to customers.

Get started with Caller ID Reputation today.