Recently, some users have run into a situation where their ChatGPT account has already been registered, but the system asks for phone verification again when logging into ChatGPT or Codex. This is especially confusing with Codex: the account was fine for signup, so why ask for a phone number when logging into the tool?

This is usually related to account risk controls, abuse of free quotas, network environment, and account security policies. Below is a summary of common causes and how to approach them.

Why phone verification is required

The most direct reason is tighter risk controls.

Once Codex opens up to users, its free quota attracts not only legitimate users but also mass registration and quota-farming. When registration bots create accounts in bulk and drain free quotas, platforms naturally tighten verification policies.

From the user’s side, the result looks like: an account that previously only needed email or third-party login is suddenly asked for a phone number when accessing ChatGPT or Codex.

This does not necessarily mean your account has a problem. It may simply be that the login environment looks risky. For example:

• You are using a network exit shared by many users.
• The current IP range has been heavily used for registrations or suspicious logins.
• The account is brand new but immediately accesses a resource-intensive tool.
• The device, region, or network changes frequently.
• Free-tier usage patterns resemble those of bulk accounts.

If you recently experienced account anomalies, login restrictions, or false bans, your network environment may have been flagged along with others using the same exit. Shared nodes used by many people carry inherently higher risk.

Why Codex triggers it more often

Codex differs from normal chat—it is closer to a development tool, potentially involves heavier resource usage, and is more attractive for bulk accounts draining free quotas.

So it is not unusual for the same account to look fine on the regular ChatGPT page but hit phone verification in the Codex login flow. Think of it as different product entry points applying different risk judgments.

For normal users, this kind of verification is usually not targeting individuals—it is aimed at curbing mass registration and quota abuse. But if your network environment is not clean, you can get caught in the crossfire.

Approach 1: Upgrade to Plus

If you use ChatGPT or Codex long-term, the simplest fix is upgrading to ChatGPT Plus.

In practice, paid accounts are generally less likely to trigger quota-abuse risk controls than free accounts. A Plus account is also better suited for stable use of Codex, advanced ChatGPT models, and other high-frequency features.

That said, upgrading to Plus does not mean you will never see another verification prompt. If it still asks for a phone number after upgrading, the common cause is still the network environment.

At this point, check:

• Whether you are on a shared network used by many people.
• Whether your exit IP keeps changing.
• Whether you have been using low-quality proxies or public nodes long-term.
• Whether many OpenAI accounts are active on the same network.

If possible, switching to a more stable and cleaner network environment before logging in is usually more effective than repeated retries.

Approach 2: Check your network environment

Many login verification problems that look like account issues are fundamentally network issues.

If a particular exit IP is shared by many users, or has been used for bulk registration, suspicious logins, or automated requests, it is more likely to be flagged. When that happens, even a legitimate user may be asked for additional verification when logging into ChatGPT or Codex.

Check from these angles:

1. Switch to a more stable network environment.
2. Avoid public, cheap, high-user-count shared nodes.
3. Minimize frequent region switches over short periods.
4. Do not rapidly switch between multiple accounts in the same browser.
5. If using a proxy, prefer lines with more stable quality and less abuse history.

You can also use third-party network quality detection tools to check the risk profile of your current IP, but such results are only a reference and do not fully represent OpenAI’s internal assessment.

Approach 3: Complete the phone verification as required

If the system explicitly asks for phone verification, the safest approach is to complete it as requested.

It is advisable to use a phone number you can keep long-term. That way, if your account later needs security verification, recovery, or alerts, you can handle them.

Do not bind important accounts to numbers of unknown origin, shared numbers, or numbers you cannot keep. It may get you through the short term, but in the long run it creates risks for account recovery, security audits, and secondary verification.

If you are using a work account, team account, or a development account you rely on heavily, you should especially avoid temporary numbers you cannot control. Account security matters more than short-term convenience.

What to watch for when upgrading to Plus

If you plan to upgrade to Plus, confirm a few things first:

• The account itself can log in normally.
• The current network environment is stable and not frequently hopping regions.
• The payment method is reliable—do not use third-party proxy payments of unknown origin.
• After upgrading, keep the payment record and account email safe.
• Do not share the account with multiple people.

Many account problems are not caused by Plus itself, but by the network, payment, and sharing habits around the upgrade. An account that is shared by many, logged into from different locations, and frequently environment-switched can trigger security verification even if it is paid.

If you are only trying it out occasionally, a free account works fine. But if you already use Codex as a daily development tool, Plus is better suited for long-term use.

Quota farming is not recommended

The free quota for tools like Codex is meant to let regular users try and experience the product. If large numbers of bulk accounts continuously drain that quota, the platform has no choice but to keep tightening risk controls.

The result is that normal users get affected too: more login friction, more verification steps, more false bans, and higher account usage costs.

For people genuinely using Codex for coding, modifying projects, and running engineering tasks, it is more worthwhile to clean up the account and network environment than to spend time dodging risk controls. In the long run, that is easier than constantly registering new accounts, switching nodes, and dealing with verification issues.

Summary

When ChatGPT or Codex asks for phone verification at login, it is usually tied to account risk controls, free-quota abuse, and network environment risk. It does not necessarily mean the account violated any rules, but it does indicate that the current login environment or account state triggered a higher verification level.

The order of action is straightforward:

1. First check the network environment; avoid shared high-risk exits.
2. If you are a long-term user, consider upgrading to Plus.
3. If the system requires phone verification, use a number you can control long-term.
4. Avoid bulk registration, account sharing, and frequent login-environment switching.

The core of stable AI tool usage is not about bypassing verification forever—it is about keeping the account, network, and usage patterns as normal as possible. That reduces login friction and lowers the chance of collateral damage later.