This article provides instructions for authorized ITS staff to add or update a user's phone number in Microsoft Entra ID Authentication Methods. This process may be required when a user cannot register their phone number through self-service, particularly when assisting international students with non-U.S. phone numbers.
When to Use This Process
Use this process when a user needs a phone number added or corrected for Microsoft authentication and is unable to complete the change through the normal self-service Security Info registration process.
This may occur when assisting international students who have a non-U.S. phone number and are unable to successfully enter or update the number themselves. Authorized ITS staff can add the phone number directly to the user's Authentication Methods in Microsoft Entra ID.
Important: Before modifying authentication methods, verify the user's identity according to the current ITS identity verification process. A user's inability to access or register an MFA method does not remove the requirement to verify their identity.
Access the User's Authentication Methods
1. Sign in to the Microsoft Entra admin center using an account authorized to manage user authentication methods.
2. Navigate to Entra ID > Users.
3. Search for and select the appropriate user.
4. Select Authentication methods from the user's account.
5. Review the user's existing authentication methods and confirm that you are modifying the correct account.
Figure 1: From the user's Microsoft Entra account, select Authentication methods.
Add the Phone Number
1. From the user's Authentication methods page, select + Add authentication method.
2. From the Choose method drop-down menu, select Phone number.
3. Select the appropriate Phone type. In most cases, select Mobile.
4. Enter the user's complete phone number, including the appropriate international country calling code.
5. Select Add.
6. Confirm that the phone number now appears under the user's Authentication Methods.
Figure 2: Select Phone number, choose the appropriate phone type, and enter the complete phone number including the country code.
Understanding Country Codes and Phone Number Format
Microsoft Entra requires the user's country calling code when an administrator enters a phone number. International phone numbers should be entered using the appropriate country calling code followed by the user's phone number.
Use the following format:
+CountryCode PhoneNumber
For example, a United States phone number may be entered as:
+1 2545551234
Common country calling codes include:
United States/Canada: +1
Mexico: +52
United Kingdom: +44
India: +91
Ghana: +233
Nigeria: +234
China: +86
South Korea: +82
Japan: +81
Formatting: Include the + symbol and country calling code. A space should separate the country code from the remainder of the phone number. Example: +1 2545551234.
International Numbers and Leading Zeros
Some countries use a leading 0 as part of the number when it is dialed domestically. This is commonly referred to as a national or trunk prefix. The leading zero generally is not included when the number is converted to international format using the country's calling code.
Do not simply place the international country code in front of the number exactly as the user provides it. Determine whether the domestic number contains a leading zero that must be removed.
Example: If a country's domestic number begins with a trunk prefix of 0, remove that prefix before adding the international country code. Confirm the correct international format when there is any uncertainty.
Ghana Phone Numbers
Ghana uses the international country calling code +233.
Ghanaian phone numbers are commonly provided domestically with a leading 0. When converting the number to international format, remove the leading 0 and replace it with +233.
For example:
Domestic format: 024 123 4567
International format: +233 241234567
Ghana: Do not enter a Ghanaian mobile number as +233 0241234567. The domestic leading 0 should be removed. The correctly converted example is +233 241234567.
Assisting International Students
International students may encounter situations where they cannot successfully enter or update an international phone number through the normal Microsoft Security Info registration process.
When this occurs, authorized ITS staff can add the phone number directly to the student's Authentication Methods in Microsoft Entra ID after verifying the student's identity.
Ask the student to provide:
• The country associated with the phone number.
• The complete phone number as they normally use it.
• The international country calling code, if known.
Convert the number to the appropriate international format before adding it to Microsoft Entra.
Examples include:
Ghana: +233 241234567
India: +91 9876543210
Mexico: +52 5512345678
United Kingdom: +44 7911123456
Security Requirement: Never add, remove, or replace an authentication phone number solely because someone provides a phone number and requests the change. Authentication methods are security-sensitive account information. The user's identity must be verified using the approved ITS identity verification process before modifying authentication methods.
Verify the Change
1. Confirm that the new phone number appears under the user's Authentication methods.
2. Have the user attempt the authentication or Security Info registration process again.
3. Confirm that the expected phone number is available as an authentication method.
4. If applicable, have the user verify that they can successfully receive the SMS authentication code or phone call.
If the user does not receive the authentication request, verify the country code and international phone number format before making additional changes.
Troubleshooting
If Microsoft Entra does not accept the phone number or the user does not receive an authentication request, verify the following:
• The correct country calling code is being used.
• The + symbol is included before the country code.
• The phone number is in the correct international format.
• A domestic leading zero or trunk prefix has been removed when required.
• The user has provided the correct and currently active phone number.
• The phone is capable of receiving the selected authentication method.
If an international number continues to fail, confirm the international dialing format with the user rather than attempting different country codes or number combinations.
Ticket Documentation
Document the authentication method change in the associated TeamDynamix ticket.
Documentation should include:
• The user's identity was verified.
• The phone authentication method was added or updated by ITS.
• The country associated with the international number when relevant.
• Whether the user successfully tested the authentication method.
Do not document the user's complete phone number, MFA codes, passwords, or other unnecessary authentication information in the ticket.
Microsoft References
Microsoft Entra administrators with the appropriate permissions can manage phone authentication methods from the user's Authentication methods page.
Microsoft Learn: Manage user authentication methods for Microsoft Entra multifactor authentication
Microsoft Learn: SMS-based user sign-in for Microsoft Entra ID