Step-by-Step Fix
1. Check the Right Email Address
Before anything else, confirm you are checking the correct inbox:
- Verify the email address you entered matches the one you are checking
- If you have multiple email accounts, check each one
- Check that there is no typo in the address (especially .co vs .com or missing letters)
2. Check All Folders — Especially Spam and Promotions
Anthropic's emails are frequently filtered. Check:
- Gmail: Promotions tab, Spam, and All Mail
- Outlook: Junk Email, and the Quarantine folder in the admin portal
- iCloud: Junk and any custom rules that might auto-delete
- Corporate email: Junk, Quarantine (requires IT or admin portal access)
- Yahoo: Spam folder
Search for "Anthropic" or "Claude" in all folders if you cannot find it by browsing.
3. Wait 10 Minutes Before Resending
Email delivery has variable timing. If you requested a code less than 10 minutes ago, wait the full 10 minutes before taking any action.
Do not click resend during this wait — each additional request adds to the queue and can cause the system to deprioritize your requests.
4. Request One New Code (Only Once)
After waiting 10 minutes with no code:
- Click resend once
- Wait another 5–10 minutes
- Check all folders again
If you have already clicked resend more than 3 times in the last 30 minutes, the rate limiter may be active. Wait 30 minutes before trying again.
5. Temporarily Disable Email Filters and Forwarders
If you use rules that auto-delete, forward, or categorize incoming mail:
- Temporarily disable those rules
- Request a new verification code
- Check if the email arrives now
Automatic forwarding chains can sometimes drop emails that contain links or codes.
6. Try a Different Email Provider
If your current email provider consistently blocks the codes:
- Create or use a Gmail account for signup — Gmail has the highest deliverability for Anthropic's emails
- Register with the new email address
7. Switch Network or Device
Some mobile networks filter outbound verification emails at the carrier level. Try:
- Switching from mobile data to Wi-Fi or vice versa
- Trying a different device
- Using a different browser
8. Contact Support
If none of the above works after 1+ hours:
- Go to support.anthropic.com
- Report that verification codes are not arriving
- Include the email address you are trying to verify and the approximate time you requested codes
Why This Happens
Claude uses email-based one-time codes for login verification. These codes are sent via a transactional email provider and are typically instant, but deliverability depends on factors outside Anthropic's control — your email provider's spam filters, corporate firewall rules, and DNS reputation. iCloud and Microsoft 365 are the most common sources of filtered Anthropic emails.
Common Mistakes to Avoid
- Clicking resend multiple times in quick succession — this triggers rate limiting and makes the problem worse
- Only checking the inbox — verification codes go to spam and promotions frequently; check every folder
- Giving up after 2 minutes — delivery can take up to 10 minutes; patience before resending is important
- Not checking for iCloud Hide My Email issues — if you used Apple's relay address, verify the relay is still active and forwarding
Prevention Tips
- Add Anthropic to your contacts — adding no-reply@anthropic.com to your contacts trains your email client to treat future messages as trusted and prevents them landing in spam
- Use Gmail when possible — Gmail consistently delivers Anthropic verification emails without filtering; if you frequently create accounts or share access with a team, maintaining a dedicated Gmail address for Claude reduces friction
- Request only one code at a time — the single most preventable cause of delayed codes is clicking resend multiple times; set a 10-minute timer after the first request before clicking resend
- Disable email forwarding during signup — if you use forwarding rules to move emails between accounts, disable them temporarily when creating a Claude account, then re-enable after setup is complete
Related Issues
Q: My verification code expired before I could use it. What should I do?
Claude verification codes have a short validity window — typically 10 to 15 minutes. If the code arrived but you did not enter it in time, request a fresh code by clicking resend. Do not try to use an expired code; it will always fail. Once you receive the new code, switch immediately to the Claude tab and enter it before doing anything else. If you have a slow email connection, keep both your email tab and the Claude tab open side by side so you can copy and paste the code as soon as it arrives.
Q: Can I use a temporary or disposable email address to sign up for Claude?
Disposable email services (like Guerrilla Mail or Mailinator) are often blocked by Anthropic's email verification system, which means the verification code either never sends or is silently dropped. Even if a temporary email address does receive the code initially, subsequent login codes sent to that address may fail — leaving you locked out with no recovery option. Use a real, permanent email address that you control and regularly check for your Claude account.
Q: I never received the initial signup confirmation email. Is my account created?
If you completed the signup form and reached a screen telling you to check your email, your account has been created in a pending state and is waiting for email verification. The account exists but is not active. Check spam and all folders for the verification email, wait up to 10 minutes, then click resend if needed. If you cannot verify the email at all, you may need to create a new account with a different email provider. The pending unverified account will eventually time out automatically.
Additional FAQ
Q: What is the fastest way to diagnose a login problem? The fastest diagnostic is to open an incognito or private browser window and attempt to sign in there. Incognito windows run without extensions and use fresh cookies, which isolates the two most common causes: a browser extension interfering with authentication, or corrupted session cookies. If login works in incognito, the issue is your main browser profile. If it still fails, the problem is your network, your account, or a platform-side incident.
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Additional FAQ
Q: What is the fastest way to diagnose a login problem? The fastest diagnostic is to open an incognito or private browser window and attempt to sign in there. Incognito windows run without extensions and use fresh cookies, which isolates the two most common causes: a browser extension interfering with authentication, or corrupted session cookies. If login works in incognito, the issue is your main browser profile. If it still fails, the problem is your network, your account, or a platform-side incident.