As an AI assistant, Claude can occasionally run into issues like account lockouts, API request failures, or message sending errors. This article rounds up the most frequent trouble scenarios and their fixes to help you get back to using it smoothly.
What to Do If Your Account Is Locked
Account lockouts usually happen after multiple incorrect password entries, logins from a new location, or triggering security controls. Try using the unlock link sent to your registered email, reset your password as prompted, and wait 15–30 minutes for it to auto‑unlock. If you still can’t log in, check that your network environment is clean—disable your VPN or switch nodes and try again.
Some users report that linking a phone number significantly reduces lockout chances. You can also enable two‑factor authentication (2FA) in your account security settings. Keep in mind that frequently switching devices or IP addresses may trigger the freeze mechanism, so try to keep your login environment stable.
API Calls Returning 400/403 Errors
The most common cause of API errors is an expired or quota‑exhausted API key. Check your key status in the Claude developer dashboard. If it shows "Expired" or "Exhausted," generate a new key or upgrade your plan. A 403 error can also happen when the Authentication header is missing—make sure every request carries the correct Bearer Token.
Additionally, if multiple processes call the same key concurrently, you may be rate‑limited. Assign separate API keys to different applications and monitor whether your call frequency exceeds the per‑minute limit. Adding a retry mechanism with exponential backoff in your code can effectively reduce the impact of temporary errors.
