STIR/SHAKEN and Why Your Calls Get Marked as Spam

STIR/SHAKEN is an industry-wide caller ID verification framework that phone carriers use to check whether a call is actually coming from the number it claims to be from.

In plain terms: when you make a call, your carrier digitally "signs" the call to confirm that you're authorized to use that caller ID number. The receiving carrier checks that signature and decides how much to trust the call.

The system was created to combat the massive wave of robocalls and spoofed caller IDs that flooded phone networks. Before STIR/SHAKEN, anyone could make a call appear to come from any number — including yours.

There are several reasons your outbound calls might be marked as spam, even if you're a legitimate business:

Your Outbound Caller ID Hasn't Been Verified

If your caller ID number isn't properly registered and verified with your carrier, the STIR/SHAKEN signature will have a low trust rating — and the receiving carrier may flag the call.

Your Number Is Newly Ported or Recently Assigned

Numbers that have recently changed carriers or were just assigned don't have an established reputation yet. Carriers tend to be cautious with unknown numbers.

You're Calling a High Volume of Numbers

If you're placing a large number of calls in a short time period, carriers may flag the pattern as robocall-like behavior — even if every call is legitimate.

Your Number Was Previously Used for Spam

If the phone number was previously owned by someone who used it for spam or robocalling, that bad reputation may still be attached to the number.

As an administrator, there are several steps you can take to reduce the chances of your calls being flagged:

1. Register and Verify Your Caller ID Numbers

Contact your service provider and make sure every outbound caller ID number your organization uses is properly registered and verified. This is the single most important step.

2. Avoid Blast-Dialing Patterns

Don't make a large number of calls to different numbers in rapid succession. This pattern mimics robocall behavior and will trigger carrier spam filters, even for legitimate calls.

3. Investigate Consistently Flagged Numbers

If a specific number is being flagged repeatedly, contact your provider to investigate. They can check the STIR/SHAKEN attestation level and work with downstream carriers to resolve the issue.

4. Check Your Outbound Caller ID Settings

Log in to the Manager Portal and verify your outbound caller ID settings. Make sure you're presenting a legitimate, assigned number — not a number you don't own or one that's been deactivated.

If you're an end user and your calls are being flagged as spam, here's what you need to understand:

• This is a carrier-level decision, not something your phone system or your admin controls directly. The receiving carrier makes the call on whether to flag your number.
• If a contact tells you your calls are showing as spam, report it to your admin immediately. The sooner they know, the sooner they can investigate and take corrective action.
• Don't try to fix it yourself by changing your caller ID settings. Presenting an unauthorized number will make the problem worse, not better.