Phone Verification for AI Tools: Which Services Ask and What to Know

Published 2026-10-01 · Updated 2026-10-01 · 9 min read

Several AI services ask for a phone number, mostly to limit spam and abuse. According to their own help pages, Claude requires phone verification when you create an account, OpenAI requires it before you create your first API key, Perplexity may ask some users to verify, and Google and Microsoft handle phone checks through the Google or Microsoft account you sign in with. Each service decides which numbers it accepts, and a phone number must never be used to exceed usage limits, create extra accounts or access a service where it is not available.

Why AI services ask for a phone number

AI tools are expensive to run and attractive to spammers, so many providers want some proof that each account belongs to a real person. A phone number is a simple check: it costs something to obtain, it can be limited to a few accounts, and it gives the provider a way to reach the account holder.

Anthropic's help page for Claude says phone verification helps prevent spam and abuse. Google's account help says phone verification is sometimes required to confirm you're a real person and to stop spammers. OpenAI's help center explains that it doesn't accept certain number types because they are often associated with higher levels of fraud or abuse.

The details below come only from each provider's own help pages, checked on 2026-10-01. Policies change, so read the linked page before you sign up. Where a provider's page doesn't say something, this guide doesn't claim it.

OpenAI (ChatGPT and the API)

OpenAI's help center says phone verification is required on its developer platform to generate your first API key, but not for later keys. Codes are sent by SMS or, in some countries, by WhatsApp; they cannot be sent by email or phone call.

OpenAI states that it does not support landlines, VoIP numbers, Google Voice or premium numbers for verification. It also limits how many times one phone number can be used for API phone verification, and its help center says it does not offer a way to change the phone number associated with an account.

OpenAI is also gradually rolling out phone-only sign-ups for ChatGPT in some countries, according to its help page on the feature. That page notes that users who sign up this way still need to verify an email to upgrade to a paid plan.

Because the number can't be changed later, use a number you plan to keep, and keep it renewed.

Claude (Anthropic)

Anthropic's help center says you're asked to verify a phone number when you first create a Claude account, by entering a code sent by text message, and that there is no option to skip this step. It says the number is used only for account verification.

The page lists number types it does not accept: VoIP numbers, Google Voice, numbers created using apps, landlines and other numbers that can't receive texts. It also says that a maximum of three Claude accounts can be verified with the same number, and that the number cannot be changed after verification.

Anthropic also says you must be physically located in one of its supported locations to create an account. A phone number from another country does not change where you are, and it must not be used to access Claude from somewhere it isn't offered.

If a code doesn't arrive, the page suggests waiting up to five minutes, trying again, entering a new code as soon as it arrives, and, after several failed attempts, trying a different number that hasn't been used for verification.

Google Gemini

Google's Gemini help page says you need a personal Google Account, a work Google Account with a qualifying Workspace edition, or a school account enabled by your institution to sign in to Gemini Apps. That page does not mention a separate phone verification step for Gemini itself.

Phone checks happen at the Google Account level. Google's account help says that phone verification is sometimes required before you create an account or sign in, to confirm you're a real person, and that Google limits the number of times a phone number can be used for verification. If a text doesn't arrive, Google suggests waiting a few minutes or choosing the phone call option.

The guide on verifying a Google account at /guides/google-account-verification-number covers the Google Account side in more detail.

Microsoft Copilot

Microsoft's getting-started page for Copilot says you can sign in to copilot.com, the Copilot mobile app or Copilot on macOS with a personal Microsoft account, an Apple ID or a Google account, and that the Copilot app on Windows requires a personal Microsoft account. That page does not mention a phone number requirement.

For personal Microsoft accounts, Microsoft has announced that it is phasing out SMS as a method of authentication and account recovery, in favor of passkeys and a verified email address. If you use Copilot with a Microsoft account, setting up a passkey is the direction Microsoft recommends.

Perplexity

Perplexity's help center says it may ask some users to verify a phone number before they continue using its apps, to help protect accounts. According to that page, you enter your number, receive a code by SMS and enter it; verification is required only once per account, and each account can be linked to only one phone number.

If verification is stopping you from getting into your account, the page says Perplexity support may be able to help.

Other AI tools

Many other AI products sign you in through an existing Google, Microsoft or Apple account, or with an email link, and some add phone checks later, for example before a free trial or when their systems flag unusual activity. Look for the provider's own help article on phone verification, and don't rely on forum posts or third-party lists, which are often out of date.

Also check whether a provider offers stronger sign-in options once your account exists, such as passkeys or an authenticator app. Where they are available, adding one gives you a recovery path that doesn't depend on a phone number at all.

Choosing a number for AI sign-ups

Several providers say a number can't be changed after verification, or limit how many accounts can use one number. That makes the number you choose more important than for most sign-ups. Use a number you intend to keep, and keep it active.

Providers also reject numbers they classify as VoIP, app-based or landline. SMS Hallo rents real mobile numbers in the local mobile format of 181 countries, and while you rent a number, only you see its messages. Even so, each provider runs its own checks and decides which numbers it accepts, so no one can promise a particular AI service will accept a particular number.

Sign up with an email address and a password, choose a country and number, and pay in USDT or USDC. Prices start from $1.80 per month on the 12-month plan ($21.60 billed yearly), the same in every country, with no setup fees. Every SMS Hallo number includes unlimited incoming SMS, unlimited incoming calls, 500 outgoing SMS per month and 1,000 outgoing calling minutes per month. The allowances reset every 30 days and unused allowance does not roll over.

Keep the number renewed or switch on auto-renew. If it expires, it may be given to someone else, and because some AI providers don't let you change the verified number, losing it could make account recovery harder.

If your number is rejected

First check the basics: the correct country, no extra leading zero, and the full number shown back to you. Wait for the countdown before asking for another code, because repeated requests can trigger limits.

If the service says the number isn't supported, retrying the same number rarely helps. Every SMS Hallo number comes with three guarantees. First, a 7-day free replacement: within 7 days you can swap the number for another available number in the same country, free, up to 3 times, and the new number keeps your plan and expiry date. Second, works or 100% refund: if the number doesn't work with the app you rented it for, for example the code never arrives, request a refund within 7 days and get 100% of what you paid. Third, a 7-day money-back guarantee: a full refund within 7 days, no questions asked, if no call or SMS has been made or received on the number.

If the provider says the service isn't available in your location, a different number will not change that and should not be used to try.

What a phone number must not be used for

AI providers set usage limits, account limits and regional availability for their own reasons, and those rules are part of their terms. Do not use extra numbers to open more accounts than a provider allows, to reset free-tier limits, to return after an account has been suspended or banned, or to reach a service from a country where it isn't offered.

SMS Hallo's Acceptable Use Policy forbids fake or duplicate accounts, fraud and breaking the terms of the apps you use numbers with. Use a number for your own single account on each service, as a private and stable contact number.

Sources

• OpenAI Help Center, What does phone verification look like?
• OpenAI Help Center, Can I use a premium number, landline, Google Voice, or other VoIP phone number?
• OpenAI Help Center, How many times can I use the same phone number to complete phone verification?
• OpenAI Help Center, How to change the phone number associated with your account
• OpenAI Help Center, Phone-only signups
• Claude Help Center, Verify your phone number
• Google Gemini Apps Help, What you need to sign in to Gemini Apps
• Google Account Help, Verify your account
• Microsoft Support, Getting started with Microsoft Copilot
• Microsoft Support, Microsoft to stop sending SMS codes for personal accounts
• Perplexity Help Center, Phone Verification for Your Account via SMS 2FA

Frequently asked questions

Related

• guides/google-account-verification-number
• guides/number-not-supported-error
• guides/what-is-a-non-voip-number
• guides/what-is-sms-verification
• guides/one-number-multiple-apps
• use-cases/app-testing-for-developers
• refund-policy

Related reading

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Last updated 2026-10-01 · SMS Hallo