Key Takeaway
Standardize your outbound caller ID everywhere. Use one authoritative phone number in E.164 format and one consistent business name (CNAM, up to ~15 characters) across platforms like Google Voice, Zoom Phone, Amazon Connect, 3CX, FreePBX, RingCentral, and Android devices so every call shows the right identity.
Update CNAM at the source and complete required verification such as STIR/SHAKEN where applicable. Propagation usually takes 24–72 hours and can take up to seven days. Always run a structured test and recheck quarterly to avoid “Spam Likely” labels.
Control who presents which number. Map caller IDs per user or queue, lock defaults, allow overrides only when needed, and test on multiple carriers to confirm what recipients actually see.
Caller ID Types: What the Recipient Actually Sees
Numeric Caller ID (CLI / E.164)
This is the phone number transmitted by the network. Always configure outbound numbers in full E.164 format with country code, such as +16505551234. This is the primary identifier carriers rely on.
CNAM or Display Name
This is the text label some networks show, such as a company name or support line. CNAM is separate from the number and is often managed through your carrier or a national registry. In some countries, CNAM is not used at all.
STIR/SHAKEN and Call Attestation
In the US and select markets, carriers use STIR/SHAKEN to verify that a call is legitimate. Calls without proper attestation may show “Not verified” or be blocked. Work with your provider to ensure your numbers are signed and registered correctly.
Why Your Outbound Caller ID Matters
When you place a call, the numeric caller ID is sent first. The receiving carrier then performs a CNAM lookup in a national database before the phone rings.
If the CNAM record is stale or missing, recipients may see an old name, a blank label, or a generic warning. Because lookup happens in real time, changes only take effect after database propagation, which can take hours or days.
Modern call analytics and mobile devices also factor in STIR/SHAKEN attestation. Unsigned or poorly attested calls are more likely to be labeled as spam.
What You Need Before Changing Settings
You need a phone number you own or have ported, your approved business name limited to about 15 characters, the number formatted in E.164, and admin access to the calling platform.
For consistency, pick one “golden” outbound number and standardize it inside your CRM so all teams dial with the same identity.
Platform-Specific Configuration
Google Voice
Google Voice displays whatever CNAM the underlying carrier has on file and does not provide an in-app toggle.
Confirm the correct number is assigned to your account.
To change the CNAM, contact the carrier that issued the number or self-list in a national CNAM database such as ListYourself.
Wait 24–72 hours, then test by calling a mobile and a landline.
Zoom Phone
Zoom allows admins and users to select from approved outbound caller IDs.
In the Admin Portal, go to Phone System Management, then Company Info, then Account Settings.
Enable Select Outbound Caller ID.
Under each user, choose the main company number or a direct number.
Optionally allow users to hide outbound caller ID when privacy is required.
Remind agents to confirm their selection before calling high-value leads.
Amazon Connect
In Amazon Connect, caller ID is defined at the queue level.
Go to Routing, select Queues, then choose a queue.
Set the outbound caller ID name and number using a 15-character name and an E.164 number.
Save and test using a contact flow tied to that queue.
Because Amazon leases numbers from multiple carriers, CNAM updates may take up to seven days.
3CX and 3CX v20
Caller ID settings differ by version.
In versions before v20, go to SIP Trunks, select the trunk, and configure the Caller ID tab or per-extension overrides.
In v20, open Admin, then Voice and Chat, open the trunk, go to Options, and configure Caller ID Control globally or by outbound rule.
Always use full E.164 formatting to avoid rejected calls or failed CNAM lookups.
FreePBX
FreePBX provides granular control through outbound routes.
Go to Connectivity, then Outbound Routes, and edit the route.
In Route CID, enter the name and number using angle-bracket syntax such as Johns Bakery <+15551234567>.
Enable Override Extension if you want the system value to override handset settings.
Apply the configuration.
Incorrect syntax is a common cause of call rejection.
RingCentral
RingCentral allows users to choose a default caller ID without admin assistance.
Go to Settings, then Phone, then Default Caller ID.
Select a company number assigned to the user or the main line.
Save changes. Mobile apps update instantly; desk phones update after resync.
For large teams, lock this setting at the admin level to maintain brand consistency.
Android Devices on Major US Carriers
Android relies on carrier “Name ID” services.
On AT&T, update through the myAT&T portal.
On T-Mobile, use the T Life app under Caller ID.
On Verizon, update through the My Verizon portal under Share Name ID.
Propagation usually takes 24–72 hours. Test by calling someone who has not saved you as a contact.
Using External Numbers in Zendesk
When forwarding calls from Zendesk Talk, standardize one outbound number to avoid exposing random direct lines.
In Zendesk Admin, go to Talk, then Lines.
Choose an external number and mark it as default.
Zendesk cannot update CNAM itself. Update the CNAM through the underlying carrier first.
Troubleshooting Incorrect Caller ID
If the wrong name appears, CNAM may not have propagated yet. Most carriers update databases twice daily, so allow up to 72 hours.
If calls are labeled spam, verify STIR/SHAKEN attestation and request full attestation from your provider.
If multiple PBX layers exist, remember that trunk settings override handset settings. Check outbound rules carefully.
Ensure no privacy codes like *67 are added automatically by dial plans.
Troubleshooting Quick Checklist
Confirm the number is sent in full E.164 format without spaces or symbols.
Verify the number is fully provisioned or ported.
Confirm CNAM registration with the carrier or registry.
Check STIR/SHAKEN attestation status for US traffic.
Ask carriers to review filtering or spam flags if calls are dropped or labeled unknown.
Five-Step Test Plan for New Caller ID
Place a test call from production to a mobile on a major carrier.
Record exactly what appears on the recipient’s screen.
If incorrect, verify CLI formatting and retry.
If the number is correct but the name is wrong, escalate to the CNAM provider.
If calls are unverified or blocked, confirm attestation and provisioning with carrier operations.
Verifying Your Work
Call both a mobile phone on a different carrier and a landline.
Use a public CNAM lookup tool to confirm the record.
Recheck quarterly, as carriers may purge inactive numbers.
Frequently Asked Questions
How long does CNAM propagation take?
Typically 24–72 hours in the US, though some carriers quote up to seven days.
Can I get outbound caller ID for free?
Most VoIP numbers include outbound caller ID. CNAM registration may involve a small one-time fee.
What if I need multiple brands on one PBX?
Use per-extension or per-queue caller ID mapping in platforms like FreePBX, 3CX, or Amazon Connect.
Does STIR/SHAKEN apply outside the US?
Canada and parts of the EU are piloting it, but enforcement varies by region.
Conclusion
A clean outbound caller ID is one of the fastest ways to look credible on every call. Choose one authoritative number, update CNAM at the source, configure platforms consistently, and verify across carriers. Set a quarterly reminder to recheck records and you will stay off spam lists while staying recognizable to customers.
Give your brand the voice and caller ID it deserves
