How to Register CNAM (Caller Name) for an ACS Phone Number

Hi @Deidad Benincasa

Thank you for reaching us regarding the issue.

We have begun looking into it and will share our suggestions with you as soon as possible. If you have any additional details or concerns in the meantime, please let us know. We appreciate your patience while we work on this.

Hi @Deidad Benincasa

To register CNAM (Caller Name Delivery) for an Azure Communication Services (ACS) phone number, follow the official Microsoft process.
Process / Steps

1. Send an email to [acstns@microsoft.com].
2. Use this (or include it) in the subject line: ACS Number Request -- CNAM Registration
3. In the email body, provide the following details:
   • Company name
   • Company website
   • Azure subscription ID
   • Azure Communication Services Resource name
   • Azure Tenant ID
   • The phone number(s) and the corresponding caller name you want registered for each number (You must own these numbers under the specified ACS resource.)

Where / How to Submit the Company Name

Submit the desired display name in the same email (paired with each number).

• Limit: 15 characters maximum (including spaces).
• Supported special characters: . (period), , (comma), & (ampersand), - (dash), _ (underscore), ' (single quote, e.g., Tom's Burgers).

Prerequisites

• Number type: US local numbers only. Toll-free numbers are not supported.
• Geographic scope: CNAM registration is currently available only for the United States. It is not supported for numbers outside the US.
• Ownership: The numbers must be owned under the Azure Communication Services resource you list in the request.
• Applies only to outbound calls from numbers you own.
• No additional formal “business ownership verification” documents are listed beyond providing the company name, website, and Azure account/resource details above. Carrier approval is still required.

Typical Turnaround Time:
Once the request is approved by the carrier, it takes approximately 48 hours for the CNAM to be published.

Important Notes

• CNAM delivery reliability varies by country/region and by the carriers that handle the call (intermediary or terminating). It is not guaranteed on every call.
• CNAM databases are not always perfectly up-to-date, so occasional inconsistencies or delays can occur.
• This is specifically for displaying a name on outbound caller ID for ACS-owned US local numbers.

Reference:
https://learn.microsoft.com/en-us/azure/communication-services/concepts/telephony/how-to-manage-your-calling-identity

Kindly let us know if the above helps or you need further assistance on this issue.

Please "upvote" if the information helped you. This will help us and others in the community as well.

Hi,

Thank you for the detailed steps, but this is exactly the process we've already followed — multiple times.

We first submitted our CNAM registration request to acstns@microsoft.com on July 8, 2026, using the exact subject line and including all required details (company name, website, Azure subscription ID, ACS resource name, Azure tenant ID, phone number, and caller name). Since then, we have followed up multiple times to the same email address and have received no confirmation, no rejection, and no status update at any point.

Our number is a US local number, owned under our ACS resource, used strictly for outbound calling — so it meets every prerequisite listed above. The issue isn't with the process itself; it's that our submissions appear to be going unanswered.

Since general guidance won't resolve this, could someone from the ACS team please:

1. Confirm whether our request was received on the backend, and
2. Provide the current status or reason for the delay, or escalate it internally if it's stuck in queue.

We're happy to resend the full details again if that helps, but at this point we need someone to actually check the backend status rather than repeat the submission process. Appreciate your help getting this escalated.

Thank you.