'%3e%3cpath%20d='M8%200C12.4183%200%2016%203.58172%2016%208C16%2012.4183%2012.4183%2016%208%2016C3.58172%2016%200%2012.4183%200%208C0%203.58172%203.58172%200%208%200ZM11.6162%204.38379C11.2257%203.99337%2010.5927%203.99338%2010.2021%204.38379L8%206.58594L5.79785%204.38379C5.40732%203.99334%204.77429%203.99329%204.38379%204.38379C3.99331%204.77429%203.99335%205.40733%204.38379%205.79785L6.58594%208L4.38379%2010.2021C3.99348%2010.5927%203.99341%2011.2257%204.38379%2011.6162C4.77426%2012.0066%205.40734%2012.0065%205.79785%2011.6162L8%209.41406L10.2021%2011.6162C10.5927%2012.0066%2011.2257%2012.0067%2011.6162%2011.6162C12.0067%2011.2257%2012.0066%2010.5927%2011.6162%2010.2021L9.41406%208L11.6162%205.79785C12.0066%205.40735%2012.0066%204.77429%2011.6162%204.38379Z'%20fill='%23080E17'%20fill-opacity='0.46'/%3e%3c/g%3e%3cdefs%3e%3cclipPath%20id='clip0_3761_713'%3e%3crect%20width='16'%20height='16'%20fill='white'/%3e%3c/clipPath%3e%3c/defs%3e%3c/svg%3e)
Fix Microsoft Developer Account Phone Number Rejected (Error 4031703)
Question details
Users attempting to sign up for a Microsoft Developer account encounter an error preventing them from completing the phone verification step.
- Product
- Microsoft Developer Account
- Device & OS
- not provided
- Scenario
- Registering for a Microsoft Developer account or Microsoft 365 Developer subscription and verifying contact details.
- Observed behavior
- The system throws error 4031703, incorrectly rejecting a valid phone number by claiming it is an unsupported, VoIP, or prepaid number.
Ensure you have your exact MS-CorrelationId and error code ready, as you will likely need to provide them to Microsoft support if self-troubleshooting fails.
Verify Phone Number Requirements and Reset Network
Ensure your phone number meets strict verification criteria and rule out browser or network glitches that might trigger the error.
Verify that your phone number is a standard mobile number provided by a major carrier. Microsoft's automated system actively blocks VoIP, virtual, and prepaid numbers.
Ensure you are entering the correct country or region code and omit any leading zeroes that are not required for international formatting.
Clear your browser cache, open an incognito window, or switch to a different internet network to rule out IP-based blocking.
If you have attempted verification multiple times, wait at least 24 hours before trying again, as the signup flow may temporarily block repeated attempts.
Contact Visual Studio Support for Microsoft 365 Developer Subscriptions
If you are obtaining your developer subscription through Visual Studio, you can contact their dedicated support team to bypass the error.
Request a Manual Investigation from Microsoft
If your standard carrier number continues to be rejected as a VoIP or prepaid number, you must escalate the issue to Microsoft support for a manual override.
Need a Reliable Office Suite? Try WPS Office
While you wait for Microsoft support to resolve your developer account verification issues, you do not have to put your work on hold. WPS Office is a free, lightweight, and highly compatible alternative to Microsoft Office that does not require complex developer subscriptions to get started.
- 1. Download the Installer: Visit the official WPS website and click the free download button.
- 2. Install the Software: Run the setup file and follow the quick installation prompts.
- 3. Open and Edit: Launch WPS Office and instantly open your existing Microsoft Office files.
Frequently Asked Questions
What does error code 4031703 mean in Microsoft Developer signup?
Error 4031703 indicates that Microsoft's automated security system has rejected the phone number provided for verification. The system usually triggers this code when it classifies the number as unsupported, prepaid, or VoIP.
Can I use a Google Voice or Skype number for Microsoft developer verification?
No, Microsoft's verification system actively blocks VoIP and virtual numbers. You must use a standard mobile number provided by a traditional cellular carrier to successfully pass verification.
Why is my regular carrier number being flagged as VoIP or prepaid?
Sometimes numbers recently ported between carriers, or numbers from specific regional carriers, are mistakenly categorized by Microsoft's security filters. Contacting support for a manual review is usually required to clear the flag.
