SMS verification for ChatGPT: when OpenAI asks for your number, and which numbers work

When OpenAI asks for a phone number

According to OpenAI's help centre, a phone number comes into play in these situations. Outside them, an email address or a Google, Apple or Microsoft login is usually enough.

• Phone-only sign-up: new users in some countries can create a ChatGPT account with just a phone number instead of an email.
• Codex in the ChatGPT desktop app: you may be asked to verify your phone number when accessing Codex there. OpenAI says email or an authenticator app doesn't replace this step.
• Your first developer key: phone verification is mandatory on platform.openai.com when you generate your initial key, but not for any keys after that.
• Multi-factor authentication: if you choose text-message MFA, you enter a phone number and receive a 6-digit code by SMS or WhatsApp at sign-in.

Where phone-only sign-up is available

OpenAI says phone-only sign-up is mostly rolled out to new users in the United States, the Netherlands, France, Spain, the United Kingdom, Poland, Germany, Japan, India, Pakistan, Algeria, Uzbekistan and Ukraine, and that no other regions are planned.

A phone-only account works differently from an email account in a few ways. Password reset happens by SMS, and OpenAI warns that resetting it requires a device you've already used at least once to log in. You can't enable MFA directly at first; you need to link an email, which you can add on the web under Settings → Account → Email → Add. To upgrade to a paid plan, OpenAI says you'll still need to verify an email. Once an email is linked, you can switch to Google, Apple or Microsoft login on the same account.

How the code is delivered

OpenAI sends verification codes by SMS or, where available, by WhatsApp. Its help centre says they cannot be sent by email or phone call. So a number that can only receive calls won't work, and there's no voice fallback if a text is slow.

The country dropdown on the verification screen defaults to the United States, so check it before you type your number. If WhatsApp is available for the country you pick, the screen may say your one-time code will go to WhatsApp. You then enter the code from WhatsApp to continue.

Channels

SMS, or WhatsApp in selected countries

Not available

Email, voice call

Default country

United States: change it if your number is from elsewhere

WhatsApp countries

United Arab Emirates, Egypt, Indonesia, Israel, India, Malaysia, Nigeria, Pakistan, Saudi Arabia, Turkey, Ukraine, Vietnam

MFA text codes

6 digits, by SMS or WhatsApp

Which numbers OpenAI accepts

OpenAI states that it does not support landlines, VoIP numbers, Google Voice or premium numbers, because those types are often associated with higher fraud or abuse. It only supports phone verification with mobile numbers over SMS, plus WhatsApp in selected regions.

In practice, numbers from internet calling services and free online inboxes are the ones most likely to be refused. If you want a number that isn't your personal SIM, it needs to be a real mobile number in the country's official mobile format. Our guide on non-VoIP numbers explains how to tell the difference.

The reuse limit: three verifications per number

OpenAI says a phone number can only ever be used for phone verification up to three times, and it doesn't offer exceptions. You could, for example, use one number to verify the first developer key on three separate OpenAI accounts. There's a second rule on top: once a number has been used for phone verification, even across multiple accounts, it can't be used to create another new account.

OpenAI's own examples make the edge cases clear. If you have two accounts that never completed phone verification, you can still sign up for a third using only that phone number. If even one of your accounts used the number for verification, that number is locked from creating any additional accounts.

• Never used for verification: the number can still create a new phone-only account.
• Used for verification once or more: no new accounts with that number.
• Up to 3 verifications in total, across all accounts.
• Deleted account: the number becomes usable again 30 days after permanent deletion, unless the account was disabled for a policy violation.

You can't change the number later

This is the rule to plan around. OpenAI's help centre says it does not offer an option to change or update the phone number on your account, for ChatGPT or for the developer platform.

That makes the number effectively permanent. If you verify with a number you later lose, such as an expired prepaid SIM, a work phone you hand back, or a short-term number you stop renewing, you can't swap in a new one. For a phone-only account that also affects password resets, which happen by SMS. Pick a number you control and plan to keep, and turn on another sign-in safeguard once you're in.

Errors and what they mean

“Too many signups with this number”

The number has already been used with OpenAI. OpenAI says recycled numbers can cause this and there's currently no workaround. Contact support or use a different number.

Number rejected as unsupported

It's a landline, VoIP, Google Voice or premium number. Use a real mobile number.

“Unsupported country”

You're signing up or creating a developer key from a location OpenAI doesn't serve. It publishes its list of supported countries and territories.

Error from a supported country

OpenAI asks you to contact Support with the exact error.

Code never arrives

Check the country in the dropdown, the number format and your signal, then request a new code.

Step by step: verifying with a number you keep

1. 01Decide which number OpenAI should hold for good, remembering you can't change it later.
2. 02Make sure it's a mobile number. Landlines, VoIP, Google Voice and premium numbers are refused.
3. 03On the verification screen, select the correct country, since the dropdown starts on the United States.
4. 04Enter the number without the domestic trunk prefix (the leading 0 many countries use) and request the code.
5. 05Enter the code from SMS, or from WhatsApp if that's what the screen offered.
6. 06Once you're in, link an email if the account is phone-only and turn on multi-factor authentication under Settings → Security and login.
7. 07Keep the number active so SMS codes keep reaching you.

Why it works with WhatsApp, Facebook, Telegram & Google

Apps check more than the digits: they look up the line type, the country format and whether the number can actually receive their code. Every SMSCreation number is a real mobile number in its country's official format — not a VoIP line — so it passes those checks the same way a SIM in your pocket does.

And we stand behind it with a 7-day replacement guarantee: if your number doesn't work with WhatsApp, Facebook, Telegram, Google or any app you need, we replace it free with a new number in the same country — or refund 100% if you prefer.

• Non-VoIP, real mobile line type — line-type checks see an ordinary SIM number, not a VoIP line
• Official country format with the right country code, prefix and digit count
• Unlimited incoming SMS and calls — codes arrive by text or through the “call me” option
• Private to you — never listed on public SMS sites, so it isn't flagged or rate-limited
• Yours for as long as you want — re-verification and account recovery keep working

Using an SMSCreation number for OpenAI

SMSCreation numbers are real mobile numbers in 181 countries, in each country's official mobile format. Every plan includes unlimited incoming SMS, and codes appear in the SMS inbox of your web dashboard. You sign up with just an email, with no ID and no phone number needed, and pay in crypto.

The permanence rules above are why keeping the number matters. Your number stays yours as long as you renew it, from $1.80 a month on the yearly plan ($21.60 billed yearly), with auto-renew from your wallet balance. If you haven't used the number for any call or SMS, you can get a refund within 7 days, no questions asked.