The “Error sending code. Double check your phone number.” message in Claude can abruptly halt your verification process, preventing access to Anthropic’s AI assistant. This frustrating roadblock typically appears during account setup or when logging in from a new device.
The Real Impact of Verification Failures
When Claude’s verification system fails, it creates more than just a minor inconvenience. Users face immediate workflow disruptions and lost productivity at critical moments. According to recent discussions on Reddit’s r/AnthropicClaude forum:
“Was in the middle of an important project and couldn’t verify my account. The ‘double check your phone number’ error kept appearing despite entering the correct format.” – Reddit user AIProductivity
“Lost access during a critical client presentation when trying to log in on my laptop. The verification system wouldn’t send the code despite my phone number being correct.” – Reddit user DataScientist
How to Fix the Claude Phone Verification Error
1. Correct Phone Number Format Issues
The most common cause is incorrect phone number formatting:
- Always include your country code (e.g., +1 for US/Canada)
- Remove any spaces, parentheses, or special characters
- Ensure you’re using the correct format: +[country code][area code][number]
Example of correct format: +14155551234 (for a US number)
2. Try Alternate Verification Methods
If available, use alternative verification options:
- Email verification (if enabled on your account)
- Use the “Problems with verification?” link on the error screen
- Try the “Use different method” option if visible during the verification
3. Address Technical Issues
Several technical factors can cause verification failures:
| Issue | Solution |
|---|---|
| Poor network connection | Switch from Wi-Fi to mobile data or vice versa |
| VPN interference | Temporarily disable VPN services |
| Browser issues | Clear cookies/cache or try incognito mode |
| App problems | Force-stop and restart the Claude app |
| Device time sync | Ensure your device clock is set to automatic |
4. Check for Service Interruptions
Verification problems sometimes stem from Claude’s systems:
- Visit Anthropic’s status page to check for reported outages
- Check Anthropic’s Twitter/X account (@AnthropicAI) for service announcements
- Search “Claude down” on DownDetector to see if others are experiencing issues
5. Contact Claude Support
If the error persists:
- Email [email protected] with your specific error details
- Include your device type, browser/app version, and when the error began
- Screenshot the error message if possible
- Provide the phone number you’re trying to use (with country code)
Recent support response times average 1-2 business days according to user reports.
Additional Helpful Information
Regional Restrictions
Claude’s verification system may not work in all countries. As of March 2025, Anthropic has expanded access to 65 countries, but verification can still be problematic in:
- Certain parts of Southeast Asia
- Some African nations
- Regions with international sanctions
Using a phone number from a well-supported region (US, UK, Canada, Australia) may resolve persistent issues.
Carrier Blocking
Some mobile carriers block automated SMS verification:
- Check if your carrier blocks automated messages or shortcodes
- Temporarily disable any SMS filtering services on your account
- Contact your carrier to whitelist Anthropic’s verification system
- Try a different phone number from another carrier if available
Account Verification Limits
Excessive verification attempts can trigger temporary blocks:
- Wait 24 hours before trying again if you’ve made multiple attempts
- Use a different phone number if available
- Create a new account as a last resort if nothing else works
Frequently Asked Questions about Claude Error
How long should I wait for the verification code?
Typically, codes arrive within 30-60 seconds. If you haven’t received it after 3 minutes, request a new one.
Does Claude work with VoIP or Google Voice numbers?
Many users report inconsistent results with VoIP numbers. Physical SIM card numbers have higher success rates for verification.
Can I use the same phone number for multiple Claude accounts?
As of March 2025, Anthropic limits one phone number to 3 Claude accounts within 30 days.
Why does Claude need my phone number?
Anthropic uses phone verification to prevent automated account creation, reduce spam, and ensure service quality.
Will international phone numbers work?
Yes, international numbers work as long as they’re formatted correctly with the country code. However, some countries have higher failure rates due to carrier issues.
Final Thoughts
By following these troubleshooting steps, most users successfully resolve the “Error sending code” message and regain access to Claude’s capabilities. If problems persist, Anthropic’s support team can provide personalized assistance to address specific verification challenges.
