Inconsistent Microsoft Teams Mobile Caller ID – FAQ

Inconsistent Caller ID (CLI) on mobile devices typically occurs when the Teams app receives incomplete call setup metadata. When this happens, the mobile device's operating system (iOS or Android) fills in the missing details using its own data sources—such as local contacts, carrier lookup databases, or third-party apps—leading to inconsistent caller display across devices or calls.

Ensure the following Microsoft Teams settings are configured:

• CallingIDSubstitute = LineUri

• BlockIncomingPstnCallerID = False

• No per-user Caller ID policy overrides

• Voice routing and SBC (Session Border Controller) configuration is valid

• No conflicting or custom Caller ID policies are applied

Correct configuration helps Teams deliver Caller ID metadata consistently to all clients.

Teams may sometimes send call setup metadata that lacks certain fields, such as:

• PhoneNumbers[0].ConfigDocs

• BlockOutgoingCallerId

This can happen due to mobile-specific factors like:

• Teams running in the background

• Network changes (e.g., Wi-Fi ↔ LTE)

• Variations in push-notification handling

These conditions may lead to incomplete CLI metadata being delivered, prompting the mobile OS to use alternate lookup methods.

When CLI metadata is incomplete, mobile operating systems may display the caller's identity using:

• Contacts stored on the device

• Outlook or Exchange directory matches

• Siri Suggestions or “Found in Apps” (iOS)

• Carrier lookup databases (e.g., Verizon, AT&T)

• Spam/caller ID apps like Hiya or TrueCaller

• Call history and cached data

Because each source can return different information, the same number may appear with different labels on different devices.

Caller ID behavior is often user-specific, influenced by:

• Individual device contact lists

• OS-level settings and permissions

• Third-party caller ID or spam detection apps

• Cached call history or prior identifications

Even with the same Teams policies, two users may see different results due to device-side differences.

Yes, organizations in GCC or GCC High environments may experience a higher likelihood of incomplete CLI delivery. These environments introduce:

• Stricter network isolation

• Alternate signaling paths

• Modified push-notification infrastructure

While these do not cause the issue directly, they increase the chance of incomplete metadata, particularly under poor signal conditions or when Teams is in the background.

Two simple tests can help isolate the behavior:

Test 1: Keep Teams open before a call

• Have the user keep Microsoft Teams in the foreground.

• If Caller ID displays correctly, it suggests the issue is related to background push-notification behavior.

Test 2: Temporarily disable OS-based Caller ID features

For iOS:

• Disable "Call Blocking & Identification" apps

• Turn off “Found in Apps” in Siri & Search

• Disable Business Lookup features

For Android:

• Turn off Google Caller ID & Spam detection

• Disable third-party services (Hiya, Samsung Smart Call, etc.)

If Caller ID becomes consistent, this confirms that the mobile OS was substituting the Teams-provided caller identity.

To reduce variability in Caller ID presentation:

• Confirm Teams policy settings are correct and uniformly applied

• Ensure Teams has all necessary permissions on mobile devices (e.g., Contacts access)

• Encourage users to keep Teams in the foreground when expecting calls

• Minimize third-party caller ID and spam apps if not required

• Educate users on how their device settings may affect CLI display