[BUG] Mobile verification problem while signing up

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?

Hi,

I am trying to sign up for Claude Code, after entering email, I was prompt to enter phone number for verification.
I'm from Serbia i tried multiple phone numbers, multiple laptops, for all numbers i got errors such as:

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

Or

"Too many verification attempts. Wait and try again later."

I've got this rate limiting error even couple of times on first try. I've been trying to sign up for couple of days.

The format of mobile number I entered was in international format for Serbia and I see that my country is on list of accepted countries.

Also, I see that in last couple of days a lot of people were posting about same issue on other platforms.

What Should Happen?

When I am prompt to enter mobile for verifying account for first time while signing up, after entering valid mobile phone in international accepted format for Serbia +381 ***** i should receive OTP code on my mobile device.

Error Messages/Logs

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

Too many verification attempts. Wait and try again later.

Steps to Reproduce

1. On the Claude Code web login page choose way of signing in
2. Choose to continue with email
3. In field for email, enter valid email address and click continue with email
4. You will receive OTP code on your email
5. Enter right code in required field
6. After successful email verification you will be redirected to https://claude.ai/onboarding
7. Accept terms and use and click create account
8. Prompt to enter mobile phone number to get verified
9. Entering mobile phone in international format +381 ***
10. Got error "Unable to send verification code to this number. Try a different number or try again later."

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

none

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_