Claude Phone Verification Code Not Sending? Fix It Now

To prevent spam and platform abuse, Anthropic requires phone verification during the sign-up process for Claude. If you are trying to log in or create an account but the SMS verification code never arrives, your carrier, phone number type, or browser settings may be blocking the transaction. Follow these practical troubleshooting steps to receive your code and unlock your account.

Why Does Claude Block SMS Deliveries? Anthropic works with major telecom aggregators (like Twilio) to verify identities. These systems aggressively filter numbers to block automated bots. Common reasons for blockages include: * Using a VOIP or virtual number (Google Voice, Skype, etc.). * Outdated cellular carrier spam settings. * Incorrect country code prefixes. * IP address geolocation mismatches.

Step 1: Ensure Your Phone Number is Eligible Anthropic does not allow virtual, landline, or prepaid VOIP numbers for security reasons.

1. Verify that your phone is a standard postpaid or prepaid mobile device linked to a physical SIM card or eSIM from a legitimate national carrier.
2. If you are using a virtual number service, stop and swap to your actual mobile number. Services like Google Voice, TextNow, and temporary SMS receiving websites will be silently rejected by the system.

Step 2: Format the Phone Number Correctly Incorrect international formatting is a major source of delivery failures.

1. Select the correct country flag and country prefix code from the dropdown menu (do not type the code manually if the system provides a dropdown).
2. Enter your main phone number. Do not include a leading zero.
3. *Example*: If your UK number is 07123 456789, choose the UK (+44) prefix and enter 7123456789 directly.
4. Remove any spaces, hyphens, or parentheses from the text input field.

Step 3: Disable Carrier and On-Device Spam Filters Aggressive filtering apps and carrier-level security measures frequently categorize automated security codes as marketing spam.

1. Disable any third-party call and text filtering applications (e.g., Truecaller, Hiya, Robokiller) temporarily.
2. On iOS, go to Settings -> Messages -> ensure Filter Unknown Senders is toggled off.
3. On Android, open the Messages app -> Settings -> Spam protection -> temporarily disable Enable spam protection.
4. Restart your mobile device to force a reconnection to local cell towers.

Step 4: Clear Browser Cache and Reset the Rate Limiter If you requested the code multiple times in a short window, Anthropic's API rate limits will block further attempts to prevent spam, even if you fix the other issues.

1. Close the Claude verification page.
2. Clear your web browser's cookies and site data for claude.ai.
3. Turn off any active VPNs or proxy services, as an IP mismatched with your phone number's country code triggers security holds.
4. Wait exactly 15 minutes without requesting any new codes. This allows the system's temporary security cooldown to expire.
5. Open a new private/incognito window, log in, and try sending the request once more.

When to Escalate If you are using a standard, contract-based mobile number from a major carrier, have formatted it correctly, have disabled spam filters, and still receive nothing after a 15-minute cool-down, contact Anthropic support at **support.anthropic.com**. When submitting your ticket, state your mobile network carrier name (e.g., Verizon, EE, Rogers) and confirm that your line is not a VOIP or virtual number so they can manually investigate routing blocks with their SMS gateway provider.