[BUG] Phone verification during signup returns error.

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Phone verification while signup returens this error
"Unable to send verification code to this number. Try a different number or try again later."

What Should Happen?

It should tell if the phone number format is not right, otherwise send the OTP.

Error Messages/Logs

Unable to send verification code to this number. Try a different number or try again later.

Steps to Reproduce

1- Go to https://claude.ai/onboarding and signup
2- Provide email and agree with the terms, proceed to next step
3- Provide the Phone number and press "send verification code" button

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

latets

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_