SMS verification for Claude: what Anthropic asks for, and which numbers work

Why Claude asks for a phone number

Anthropic says verifying your phone number helps it prevent spam and abuse. It also says the number is only used for account verification and not for any other purposes. It isn't how you sign in: after sign-up, you log in to Claude with a secure link sent to your email or with "Continue with Google". Claude accounts don't have a dedicated password.

The step comes at the very start. When you first create a Claude account, you're asked for a phone number from a supported location. Anthropic says only users physically located in one of its supported locations can create and use Claude accounts, and a phone number from a supported location is required as well.

How the code is delivered

Anthropic sends a six-digit verification code to your number by text message. You type it into the box on the verification screen and click "Verify code". That confirms you have access to the number and completes account creation.

The help centre only describes text message delivery. So the number you use has to receive SMS; a number that can only take calls won't get you through.

Channel

Text message (SMS)

Code length

6 digits

Button to press

"Verify code"

When

When you first create a Claude account

Can you skip it?

No: Anthropic requires it for all new users

Which numbers Anthropic refuses

Anthropic lists the types of number it won't accept for verification. If yours falls into one of these groups, the check won't go through however many times you try.

• VoIP numbers
• Google Voice numbers
• Phone numbers created using apps
• Landlines
• Any other number that can't receive texts
• Numbers from outside Anthropic's supported locations

The three-account limit

Anthropic allows a maximum of three Claude accounts to be verified with the same phone number. If you try a number that has already verified three accounts, you'll see an error saying the number is already in use or has been used too many times.

There are two ways out. If you know which email addresses belong to the accounts that used the number, log in to one of them and contact Anthropic's Support team to ask for the number to be unlinked. Once it's unlinked, the number can verify a different account. Or enter a different phone number that hasn't been used for verification yet.

You can't change the number later

This is the rule to plan around. Anthropic's help centre says there isn't a way to change the phone number on your Claude account once it has been verified, and it asks you to verify with a number you'll have access to long-term.

That makes the choice effectively permanent. A prepaid SIM that expires, a work phone you hand back or a short-term number you stop paying for all leave you with a verified account tied to a number you no longer control. Pick a number you plan to keep.

Errors and what they mean

No code after a few minutes

The text can take a few minutes. After more than five minutes, click "Try again" to reset the window and re-enter the number, checking it's correct.

"Error sending code. Double check your phone number."

If this persists, or the code still doesn't come after re-entering the number, Anthropic says to use a different phone number.

The code isn't working

Codes are temporary. Use the most recent one, or click "Try again" for a new code and enter it right away.

Number already in use

Three Claude accounts are already verified with it. Ask Support to unlink it from one of your accounts, or use another number.

Location not supported

You must be physically in a supported location to create and use an account.

Phone verification is not identity verification

Anthropic also runs a separate identity check. It says it's rolling out identity and business verification for a few use cases, and you might see a prompt when accessing certain capabilities, as part of routine platform integrity checks, or for other safety and compliance reasons. Its verification partner is Persona.

That check needs a valid, physical government-issued photo ID and a phone with a camera for a possible live selfie. Photocopies, screenshots and digital IDs aren't accepted. No phone number, ours included, can stand in for it. If you're asked to verify your identity, only your own documents will do.

Step by step: verifying with a number you keep

1. 01Check that you're physically in one of Anthropic's supported locations.
2. 02Choose the number Claude should keep for good, since you can't change it later.
3. 03Make sure it's a mobile number that receives texts. VoIP, Google Voice, app-created numbers and landlines are refused.
4. 04Enter the number when Claude asks, and wait for the six-digit code by text message.
5. 05Type the code and click "Verify code". If nothing arrives after five minutes, click "Try again" and re-enter the number.
6. 06Keep the number renewed, and remember it can verify no more than three Claude accounts.

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 Claude

SMSCreation numbers are real mobile numbers in 181 countries, in each country's official mobile format, and every plan includes unlimited incoming SMS. Your code appears in the SMS inbox of the web dashboard. You sign up with just an email, with no ID and no phone number needed, and pay in crypto. The number doesn't change where you are, so Anthropic's supported-location rule still applies to you.

Because Anthropic won't let you change the number, keeping it is what counts. 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.