Error Code 40902 during M365 E5 Developer Program registration

Question

I am currently trying to set up my Microsoft 365 E5 Developer subscription sandbox, but I am completely blocked at the security phone verification step.

Whenever I enter my phone number and click "Send Code", the system immediately blocks the process with an error message, even though this is a valid phone number. I also tried different phone numbers.

Here are the details of the issue and the error log captured from my dashboard:

Error Message: "We can't continue with the signup process for the following reason: You have used too many phone numbers."

Error Code: 40902

MS-CorrelationId: [Moderator note: personal info removed]

I have already tried clearing my browser cache, using an Incognito window, and waiting before retrying, but the issue persists. This developer tenant is highly critical for my ongoing M365 technical training and hands-on labs.

Answer 1

I initially started creating the account last Wednesday. After encountering the error, I waited 24 hours, then tried again the next day, and the day after that before stopping. I completely paused all attempts over the weekend and only tried again this week, but the issue still persists.

I have tried multiple different web browsers and also utilized Incognito/InPrivate sessions, but I still receive the exact same error. The phone number I am using is completely new and has never been linked to or used for any other Microsoft Developer Program account in the past.

I am using a standard residential internet connection and have ensured that no VPNs, corporate proxies, or public DNS services are active during my registration attempts.

Answer 2

Please note that Q&A forum is a public platform, and moderators will modify the question to hide personal information in the description. Kindly ensure that you hide any personal or organizational information the next time you post an error or other details to protect personal data.

Hi @Shelly Duong

Based on your description, I understand that you are completely blocked while attempting to set up your Microsoft 365 E5 Developer subscription sandbox. Whenever you input a phone number at the security verification stage, the platform immediately rejects the registration with Error Code 40902: "We can't continue with the signup process for the following reason: You have used too many phone numbers." This block occurs instantly despite using valid numbers, trying alternative numbers, clearing your browser cache, and utilizing Incognito sessions.

The error “You have used too many phone numbers” with Code 40902 is generally related to the automated phone verification and anti-abuse checks used during Microsoft 365 Developer Program signup.

-Just to check, how long did you wait before trying again?

-Have you tried using a different browser yet?

-Has the phone number you are using ever been linked to any other developer program account in the past?

-Also, please avoid using a VPN or a corporate proxy, as certain networks or IP addresses can be flagged as high-risk by the authentication system.

Since we are on a community forum, moderators can only provide guidance based on official documentation and do not have backend access to the automated Developer Program systems. Please share any additional details you have so we can figure this issue out together!

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