How to Fix Office 365 E5 Phone Verification Errors 40315 and 40902
Question details
The user is unable to complete the Office 365 E5 setup due to phone-number authentication failures, specifically receiving error 40315 for a security check failure and error 40902 for using too many numbers.
- Product
- Microsoft Office 365 E5
- Device & OS
- not provided
- Scenario
- Setting up a new Office 365 E5 subscription and attempting to authenticate via phone verification.
- Observed behavior
- The system rejects the initial phone number with error code 40315, and subsequent attempts with a different number fail with error code 40902.
Stop attempting to verify with new phone numbers to prevent triggering further account lockouts, and have your Office 365 E5 account details ready for support verification.
Contact Microsoft Business Support to Allowlist Your Phone Number
Errors 40315 and 40902 are backend security blocks that cannot be bypassed manually. You must contact Microsoft support to have your phone number reviewed and allowlisted.
Microsoft's automated security systems occasionally flag phone numbers during the Office 365 E5 setup, resulting in error 40315. Repeated attempts with different numbers will trigger error 40902 (rate limiting). Resolving this requires manual intervention from the Microsoft support team.
Navigate to the official Microsoft 365 admin help page using your web browser.
Look for the country-specific business support phone numbers listed for your region.
Call the support line, explain that you are receiving verification errors 40315 and 40902 during your E5 setup, and request a phone number security review to unblock your account.
Try WPS Office While Waiting for Account Verification
If your Office 365 setup is delayed by verification errors, you can stay productive with WPS Office. It is a completely free, lightweight alternative that requires no complex setup and offers full compatibility with Microsoft file formats.
- 1. Download WPS Office: Visit the official WPS website and download the free installation package for your operating system.
- 2. Install and Open: Run the installer. Once complete, open the application to access Writer, Spreadsheets, and Presentation modules.
- 3. Resume Your Work: Open your existing .docx, .xlsx, or .pptx files and continue working without waiting for your Office 365 account to be unlocked.
Frequently Asked Questions
What does error code 40315 mean in Office 365 setup?
Error 40315 indicates that the phone number provided for MFA or setup did not pass Microsoft's automated security checks. The system flags the number as potentially suspicious, requiring manual review by support.
Why did I receive error 40902 after trying a second phone number?
Error 40902 is triggered by rate limiting. It appears when the system detects that too many phone numbers have been submitted or too many verification requests have been made in a short period of time.
Can I use a VoIP or virtual phone number for Office 365 verification?
Microsoft frequently blocks VoIP, internet-based, or virtual phone numbers for security reasons. Using these numbers is a common cause of error 40315. It is strongly recommended to use a standard mobile or landline number.
How long does it take for Microsoft to unblock my phone number?
Once you submit a ticket or call Microsoft business support, it typically takes 24 to 48 hours for their backend team to review the request and allowlist your phone number.
