Teams Phone System - local company phone numbers are not recognized as contact names

Hello @Slobodan Dojcinovic, 

I understand why this behavior can be confusing, especially since the phone numbers are correctly synchronized and work when entered in full format. 

I reviewed the Teams calling behavior against Microsoft’s dial‑pad and calling logic documentation, and what you are seeing seems aligning with how the feature is implemented:

When digits are entered in the Teams dial pad, the client treats the input as a dial string and prioritizes calling logic rather than doing a full directory search. It then attempts to resolve a name by matching the number against a limited set of sources, mainly tenant‑assigned phone numbers (numbers assigned as part of Teams Phone) and contacts stored in Exchange or Outlook. This behavior is consistent with how Teams processes dialed input and routes calls using normalized numbers.  

For your reference: Teams Dial pad configuration - Microsoft Teams | Microsoft Learn 

In practice, this explains the difference you are observing. Users who have Teams Phone and an assigned number are included in the calling dataset, so their identity can be resolved when dialing. Users who do not have Teams Phone may still have a phone number stored in Entra ID, but that number is not part of the calling dataset used by the dial pad for resolution, which is why typing only a 4‑digit extension does not return their name. 

When you dial a longer number such as the prefix plus the extension, it becomes closer to the full E.164 format stored in the directory. In that case, Teams can match it either through its normalized number processing or through contact lookup, and the name is displayed. 

This also aligns with Microsoft’s description of dial plans. Dial plans and normalization rules are used to translate user input into a standardized format for routing, typically E.164. They ensure that numbers entered in different formats can be processed and routed correctly, but they do not guarantee that a corresponding user name will be resolved or displayed. 

For your reference: Microsoft Teams Dial plans for phone call routing - Microsoft Teams | Microsoft Learn 

Because of this separation, it is possible for a short number to route correctly (after normalization) but still not display a name if the resulting number is not matched against a supported lookup source for the dial pad. 

If you want to improve the behavior, the typical approaches are to use dial plan normalization so that short extensions are consistently translated to full numbers, or to ensure the numbers are present in Outlook or Exchange contacts, since those are part of the lookup sources. For scenarios where extension dialing is a core requirement, Microsoft generally positions Auto Attendant with dial‑by‑extension as the feature designed for that purpose. 

Based on this, your current setup is functioning as expected given how the Teams dial pad resolves numbers. 

However, this is what I’ve been able to find so far that is related to the issue. I was not able to find any official Microsoft documentation that directly mentions or fully confirms this specific behavior. Additionally, I currently don’t have the resources available to reproduce and validate this scenario in a test environment. 

Given this, if you need a formal confirmation or clarification, I recommend contacting Microsoft Support. The Microsoft Support team can validate whether the behavior is expected within your specific tenant and configuration, perform backend checks that are not visible from the admin side, confirm if there are any service limitations, known issues, or changes in behavior and provide official guidance or escalate internally if further investigation is needed.

For business support:   

• Find your Microsoft 365 admin: If you don't know who the global admin is in your organization, you can find guidance here: How can I find my Microsoft 365 admin? - Microsoft Support    
• Submit a service request: The Global Administrator should create a support request with Microsoft to receive advanced technical assistance. For detailed instructions, see: Get support - Microsoft 365 admin | Microsoft Learn  
• If your organization's subscription is from a partner or reseller, contact the reseller's support provider to help open a service request on behalf of you instead.    

This would be the most reliable way to get a definitive answer. If you discover any solutions or have additional insights, please consider replying to this thread to help others in the community.   

I’m sorry for any inconvenience this situation may be causing. I’d like to be transparent that, as forum moderator, I don’t have access to internal backend systems or the ability to escalate this directly to the Microsoft Product team. However, I’ll do my best to guide you based on the available information and help point you toward the most appropriate next steps if needed.

I hope this suggestion helps. Please feel free to leave a comment if you need any further assistance or need any clarifications. 

Thank you again for reaching out! 

If you have extra questions about this answer, please click "Comment". 

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