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

Question

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

Deidad Benincasa 0

Hello,

We have a phone number provisioned through Azure Communication Services and would like to register CNAM (Caller Name Delivery) so our company name displays on outbound caller ID instead of just the number.

Could someone please guide us on:

The correct process/steps to register a CNAM entry for an ACS number
Where to submit the company name we want displayed (within the 15-character limit)
Any prerequisites (e.g., number type, carrier support, verification of business ownership) needed before CNAM can be approved
Typical turnaround time once submitted

This is for a US local number used for outbound business calling. Any documentation links or the correct submission channel would be greatly appreciated.

Thanks in advance for your help!

Golla Venkata Pavani 7,270 Reputation points Microsoft External Staff Moderator

2026-08-03T10:46:04.0166667+00:00

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.
Golla Venkata Pavani 7,270 Reputation points Microsoft External Staff Moderator

2026-08-03T12:19:22.9166667+00:00
Hi @Deidad Benincasa

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

Send an email to [acstns@microsoft.com].

Use this (or include it) in the subject line: ACS Number Request -- CNAM Registration

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.
Deidad Benincasa 0 Reputation points

2026-08-04T06:12:00.62+00:00
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:

Confirm whether our request was received on the backend, and

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.
Golla Venkata Pavani 7,270 Reputation points Microsoft External Staff Moderator

2026-08-06T10:02:57.51+00:00

Hi @Deidad Benincasa

Thanks for your response.

We have shared a link via private chat to create a support ticket. Please fill the form to investigate the issue further.

2 answers

Your answer

Golla Venkata Pavani 7,270 Reputation points Microsoft External Staff Moderator

2026-08-03T10:46:04.0166667+00:00

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.
Deidad Benincasa 0 Reputation points

2026-08-04T06:12:00.62+00:00

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:

Confirm whether our request was received on the backend, and

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.
Golla Venkata Pavani 7,270 Reputation points Microsoft External Staff Moderator

2026-08-06T10:02:57.51+00:00

Hi @Deidad Benincasa

Thanks for your response.

We have shared a link via private chat to create a support ticket. Please fill the form to investigate the issue further.

Answer 1

Deidad Benincasa 0

Is there any update regarding this question?

Deidad Benincasa 0 Reputation points

2026-08-05T04:55:41.1766667+00:00
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:

Confirm whether our request was received on the backend, and

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.

Answer 2

Thank you for the detailed guidance — this matches the format we used.

We had already submitted a CNAM registration request via email to the ACS telephony team on July 8, 2026, following this exact structure (company name, website, subscription ID, resource name, tenant ID, phone number, and caller name), but we haven't received any confirmation or status update since then.

Since the documented guidance says to open an Azure support request when no confirmation is received, we'll go ahead and do that to have the ACS team check the backend status. Just wanted to flag here in case others are experiencing the same delay — is there a typical response time we should expect before escalating, or any other channel worth trying in parallel?

Thanks again for the help.