Why VoIP Virtual Numbers Can't Register for ChatGPT: Platforms Check Line Type Before Sending Codes

OpenAI queries the phone number's line type before sending a verification code, and VoIP, Google Voice, and landline numbers are blocked outright, so resending or changing networks won't help. This article explains the detection mechanism, which numbers can pass (real carrier numbers with a Mobile line type), and how to decide between short-term and long-term numbers before switching.

2026 Latest Codex Phone Verification Guide: How to Solve ChatGPT Phone Verification in China

A comprehensive guide for Chinese users to bypass OpenAI's phone verification for Codex, covering methods using overseas SIM cards and SMS reception platforms like NexSMS.