A plumber in Calgary returns a missed call. It rings on the customer's end — but instead of the business name, the screen reads "Spam Likely." The call slides to voicemail, and the homeowner who phoned twenty minutes earlier now assumes a scammer is ringing back. The job goes to whoever picks up first.
This is the quiet tax creeping onto Canadian businesses in 2026, and it bites hardest the moment you let an AI voice agent place calls for you. If your outbound calls keep landing in the spam bucket, it usually isn't because you broke a rule. It's because of how Canada now authenticates every phone call — a framework called STIR/SHAKEN — and because the CRTC spent 2026 tightening the rules around nuisance calls. Here is what's actually going on, from Vancouver to St. John's, and how to keep your number trusted.
Why "Spam Likely" lands on legitimate calls
Your phone carrier doesn't decide a call is spam by reading your intentions. It leans on two things: a cryptographic signature attached to the call, and a reputation score built from how people have treated calls from your number. When either looks weak, call-screening apps and the dialer's own built-in filters slap a warning on your caller ID — or hide the call entirely.
STIR/SHAKEN is the signature half. The acronym is a mouthful (Secure Telephone Identity Revisited, and Signature-based Handling of Asserted information using toKENs), but the idea is simple: when your carrier sends a call onto the network, it digitally signs it to vouch that the number is really yours. The CRTC directed Canadian carriers to deploy it in Telecom Decision CRTC 2021-123, and it now runs across the IP-based networks that carry most business calls. The receiving carrier reads the signature and asks one question: how much should I trust this?
How STIR/SHAKEN digitally signs a call as it passes between carriers
The three levels of trust your calls can earn
Every signed call carries an attestation level, and this is where a lot of honest businesses quietly lose ground:
- Full attestation (A) — your carrier knows exactly who you are and has confirmed you have the right to use the number you're calling from. This is the gold standard, and it's what gets your call through clean.
- Partial attestation (B) — your carrier knows you as a customer but can't confirm the specific number is yours. Common when calls route through a cloud platform or a borrowed caller ID.
- Gateway attestation (C) — the carrier is just passing the call along and can't vouch for the origin at all. International and heavily-relayed traffic often lands here.
Here's the catch for anyone running an AI voice agent: these agents usually dial through a cloud telephony provider — the plumbing behind platforms like Twilio, Vapi, or Retell. If the number you display isn't properly registered to the account placing the call, you can slip from A down to B or C without ever knowing. Lower attestation plus a fresh, low-reputation number is the exact recipe for a "Spam Likely" tag.
What changed in 2026: the traceback mandate
2026 is the year the CRTC stopped treating bad-actor calls as someone else's problem. In Compliance and Enforcement Decision CRTC 2026-52 (27 March 2026), the Commission made participation in call traceback mandatory for every provider of voice services in Canada, as a condition of service effective 25 June 2026. In plain terms: when a suspicious call is reported, carriers must cooperate to trace it back to its source — naming the upstream carrier, keeping call records for at least ten days, and responding within two business days.
The decision also requires carriers to pass along the signing provider's identity and the attestation level when they respond to a traceback request. Read that twice. The attestation on your calls is no longer a quiet technical footnote — it's data that follows your traffic around the network. For a Toronto clinic or a Winnipeg contractor running automated reminders, that makes a clean, fully-attested number more valuable than ever.
None of this forces carriers to block unsigned calls outright; Canada hasn't gone as far as the United States on automatic blocking. But between tighter traceback, aggressive carrier analytics, and the spam-filtering apps on nearly every phone, the practical result is the same: weakly-authenticated calls get buried.
A verified business call gets answered with confidence
The real cost of a flagged number
Put rough numbers on it. Say your AI agent makes 300 outbound calls a month — reminders, callbacks, confirmations. If a third are getting flagged and ignored, that's 100 conversations that never happen. You don't lose 100 jobs; most of those calls wouldn't have converted anyway. But if even 15% of answered calls turn into booked work worth an average of $300, those 100 missed connections quietly cost you roughly $4,500 in a single month — and you'd never see it on an invoice, because the revenue simply never arrived.
That's the frustrating part. A flagged number doesn't throw an error. It just makes your business slowly invisible, one unanswered call at a time, while the competitor down the street — whose number happens to be clean — looks more responsive than you.
Where your AI voice agent helps, and where it can hurt
An AI voice agent cuts both ways here. On the inbound side, it's a genuine shield: it can answer the flood of robocalls and screen junk before a human ever picks up, which we walk through in our guide to screening spam calls with an AI voice agent. The agent never gets tired and politely ends the calls that are obviously fake.
On the outbound side, the same automation that lets you send a hundred appointment reminders before lunch is exactly what spam filters are built to notice. Volume, repetition, and short call durations are classic spam signals. If you're using an agent for appointment reminders that cut no-shows, the goal isn't just to make the calls — it's to make them land with your business name showing, not a red flag.
A Canada-wide checklist to keep your calls trusted
You can't personally sign your own calls — that's your carrier's job — but you control most of what feeds the trust score. Work through this list:
- Register your numbers properly. Every number your agent displays should be formally assigned to the account placing the call. This is the single biggest lever for earning full (A) attestation. If you use a cloud platform, ask them point-blank what attestation level your calls carry.
- Talk to your telecom provider about KYC. Carriers tie attestation to "know your customer" checks. A quick call to update your business details can be the difference between an A and a B.
- Display a consistent, local caller ID. A Halifax business calling Halifax customers from a recognizable local number earns trust faster than a rotating or out-of-province number. Consistency builds reputation; churn destroys it.
- Keep call volumes human. Blasting thousands of near-identical short calls is the fastest way to get labelled. Space campaigns out and give the agent real conversations to have.
- Honour the rules on unsolicited calls. Respect the National Do Not Call List and Canada's anti-spam rules — the CRTC's telemarketing and DNCL rules apply to automated calls too. A clean compliance record protects your number's reputation.
- Monitor your reputation. Several free tools let you check whether your number is being flagged. Catch it early, and a quick provider ticket can often clear it.
Quick answers
Does STIR/SHAKEN block my calls?
Not directly — it authenticates them. But a low authentication level feeds the carrier and app filters that decide whether to show "Spam Likely" or send your call straight to voicemail.
Will a new phone number fix it?
Rarely, and often only for a while. A brand-new number has no reputation, which can be just as suspicious to the filters. Fixing registration and attestation on your existing number is usually the better move.
Is this different in Quebec or the territories?
The federal rules are the same coast to coast — the CRTC regulates calls across every province and territory. Local caller-ID consistency still matters most where your customers actually are.
Trust is the new deliverability
For years, businesses obsessed over email deliverability: spam folders, sender reputation, authentication records. Phone calls are now going through the same shift, and Canada's 2026 rules have accelerated it. A call that doesn't look authenticated is a call that doesn't get answered, no matter how good your offer or how friendly your AI voice agent sounds.
The upside is that this rewards the businesses doing it right. If your numbers are registered, your attestation is full, and your agent has genuine, well-spaced conversations, you stand out in a sea of flagged junk. That reliability compounds — and it feeds the bigger question of whether Canadians can trust an AI voice agent on the other end of the line.
Spam-flagging isn't a glitch you wait out. It's the new baseline, from the Pacific to the Atlantic time zones. Treat your phone number like the business asset it is, keep it clean and fully attested, and your AI voice agent becomes what it's supposed to be: the reason customers pick up, not the reason they don't.