Why do ChatGPT and OpenAI ask for phone verification? Failure reasons and how to get the code

Learn why OpenAI verifies phone numbers and when it asks, the common failure cases and how to handle them, and how to choose a country and receive the SMS code with a temporary number.

When you create an OpenAI account, use ChatGPT or set up the API platform, you may be asked to enter a phone number and type in an SMS code. Many people get stuck here with messages like “number not supported” or a code that never arrives. This guide explains why OpenAI verifies phone numbers, the most common reasons verification fails, and what to keep in mind when you use a temporary number.

Why phone verification is required

When you register an account or use the API, OpenAI asks you to link a phone number and enter an SMS code to prevent bulk sign-ups and abuse. One phone number can usually be linked to only a limited number of accounts, so the number effectively works as a quota.

When verification is requested

• Creating an account: in some regions or situations, you need to verify a phone number when you sign up.
• Using the API platform: setting up the developer platform, creating an API key or claiming credits often requires phone verification.
• Account security checks: signing in from a new device or network, or unusual account activity, can trigger verification again.

Common reasons verification fails

• Number already used: the number has reached its account limit, so you need a new number.
• Number type not supported: some internet phone numbers are rejected; you need a mobile number that can receive SMS.
• Country not supported: the number usually needs to be from a country or region that OpenAI supports.
• Too many requests in a short time: this triggers a rate limit, so wait a while before trying again.
• Wrong country code: the country code was entered twice, or the leading 0 used for domestic calls was kept.

Receiving the code with a temporary number

If you would rather not use your personal number, choose a temporary number that can receive SMS:

1. On the OpenAI SMS page, choose a country and a number.
2. Enter the number on the OpenAI page and request the code.
3. Read the 6-digit code in the SMS on your order page and enter it.
4. Once verified, set up email sign-in and your security settings right away.

If OpenAI says the number is not supported as soon as you submit it, the problem is the number itself, and waiting will not bring an SMS. Just cancel the order and try another number or country; orders that do not receive an SMS are not charged.

Which country to choose

Prefer countries that OpenAI serves and that have plenty of stock. US numbers have wide coverage, and you can compare prices on the US virtual number page. Ideally, the number’s country should match your network region; a large mismatch can trigger extra security checks. If you are not sure how temporary numbers work, read What is an SMS verification service? first.

After verification

Phone verification is only the first step. So that your account does not depend on the temporary number later, we recommend these settings:

• Confirm how you sign in: use an email and password, or link a third-party account you use regularly.
• Turn on multi-factor authentication: enable an authenticator app in your security settings to protect the account.
• Keep API keys safe: never put keys in public code or chat logs, and revoke them promptly if they leak.

What to do when verification fails

1. Read the message first: “not supported” means the number was rejected, so switch numbers right away; a message about too many requests means you need to wait.
2. Check the country code and number format, and do not enter the country code twice.
3. Switch to another country with plenty of stock instead of trying number after number in the same country.
4. If it still fails, check whether a VPN is changing your network location, or whether you have registered several accounts in a short time.

Following this order usually gets you verified faster and avoids longer restrictions caused by repeated requests.

Things to keep in mind

A temporary number is recycled when it expires, and you will not be able to use it for OpenAI messages again, so do not treat it as a long-term account recovery method. Before using it, read OpenAI’s terms of service and follow local law.

FAQ

Why does it say “this number is not supported”?

Usually the number type or country is not accepted, such as an internet phone number or a country outside the supported list. Switch to a mobile number from a supported country instead of retrying the same number.

How long does the code take to arrive?

It usually arrives within a minute or two. If nothing arrives before the order expires, cancel the order and try a different number.

How many accounts can one number verify?

OpenAI limits how many accounts can be linked to one number, and the exact limit may change. To avoid rejections, use a different number for each account.

Will I need this number again later?

Normal sign-in usually relies on email or a third-party account, not SMS. But if OpenAI asks you to verify a phone number again in the future, the temporary number will no longer receive codes, and you will need to verify with a new number.

Do ChatGPT and the API platform need separate verification?

ChatGPT and the API platform use the same OpenAI account, so a verified phone number usually counts for both. If the platform asks you to verify again at some point later, you will need a number that can receive SMS at that time.

If the SMS does not arrive, check the Help center first.