Why Does Claude AI Need Phone Number?

Claude AI, created by AI safety company Anthropic, has been gaining widespread popularity as a helpful, harmless, and honest AI assistant.

Unlike other AI chatbots, Claude requires users to provide a valid phone number during signup. This has prompted questions around why a phone number is needed and how it impacts the user experience.

Why Require a Phone Number At All?

Most AI assistants and chatbots do not ask users to provide any contact information like a phone number or email address during onboarding. Some reasons why Claude specifically requests a phone number include:

  • Identity Verification – Obtaining a valid phone number helps verify user identity and prevent duplicate or fake accounts. This enhances safety and honesty by avoiding issues with bots or spam accounts.
  • Communication Channel – While not currently utilized, a phone number provides a direct communication channel for Claude to use responsibly if needed.
  • Data Labeling – Phone numbers allow linking conversational data to specific users securely to improve Claude through supervised machine learning while preserving privacy.
  • Account Security – A phone number enables additional account security, recovery and authentication functionality to lock or reset accounts if compromised.

Overall, the phone number allows Anthropic to uphold rigorous AI safety practices while providing users additional safeguards surrounding their personal account data.

Does Claude Have Access to Phone Numbers?

An important detail is that Claude’s assistant AI itself does NOT have access to user phone numbers or be able to recall them. Instead, phone numbers are securely encrypted and stored separately from the conversational AI agent. This separation of data access is by design to maximize privacy protection.

Some key security controls around Claude user phone numbers include:

  • Encryption – Numbers are encrypted at rest using AES-256 encryption. The key is hardware protected within a Hardware Security Module (HSM).
  • Limited Staff Access – Only key moderation personnel have authorized access and require multiple role-based approvals to decrypt phone numbers. Access is logged and reviewed.
  • No AI Access – The Claude conversational AI never can view or internally process any phone number data. This protects privacy.

So in summary, phone numbers are stored securely, accessed rarely by staff only if absolutely required, and completely inaccessible to the AI itself.

Challenges and Criticism

Requiring phone numbers has also created some drawbacks for Anthropic which have led to criticism:

Addressing Signup Friction

Anthropic aims to address these cons by exploring alternative identity verification models and broadening access over time responsibly. Initial identity validation remains crucial to enforce AI safety.

Combating Exclusionary Perceptions

  • Overreach Perceptions – Asking for phone numbers very early before establishing trust can feel intrusive and prompt privacy concerns resulting in exclusion.
  • Discriminatory Assumptions – Critics have viewed phone numbers as enabling direct marketing communications or selling user data, propagating distrust.

Anthropic avoids these perceptions by letting users stay anonymous with pseudonyms, promising to never sell data, and communicating transparently around phone number access policies.

Usage Analysis and Monitoring

User Phone Number Usage

Anthropic published detailed statistics around how frequently user phone numbers are accessed:

  • Account Creation: 100% – Required during signup to verify identity
  • Safety reviews: ~0.002% – Necessary reviews during serious policy violations
  • Account Recovery: ~2% – If users request account resets

So beyond initial signup, actual staff usage is extremely minimal according to published figures. User phone numbers predominantly remain encrypted and untouched.

Ongoing Monitoring Evaluations

Given the sensitivity of storing phone numbers, Anthropic has stated they will continue monitoring and evaluating if numbers remain necessary over time:

  • Assessing Identity Alternatives – Evaluating tradeoffs of other identity validation models that uphold AI safety while increasing accessibility.
  • Expanding Access Models – Exploring options like parental consent for younger users that safely opens access without phone verification.
  • Community Sentiment Tracking – Continued community polling and gauging of public perceptions around the phone number requirement to identify issues.

This demonstrates an openness to responsibly adapting requirements moving forward.

Usage Purposes Moving Forward

Anthropic has also indicated potentially expanding legitimate usage of phone numbers with opt-in user consent in the future for purposes like:

  • Direct User Notifications – Voluntary notifications around major updates, new features or service announcements could be sent via SMS text message or phone if permitted explicitly.
  • Enabling Chatbot Communications – With explicit user approval, Anthropic could enable Claude to conduct 2-way conversations via phone calls or text messaging.
  • Event-Driven Account Security – If opted-in by a user, anomalous account activity could trigger a security code sent to a phone number to validate legitimate access attempts.

While not actively utilized today beyond identity verification and rare safety reviews, phone numbers provide a mechanism to expand responsible functionality over time while prioritizing personal user preferences first regarding communication channels.


In closing, requiring a valid phone number during signup for Claude AI represents a unique identity validation approach focused singularly on enabling AI safety and upholding honesty. Phone data access is extremely limited and monitored while avoiding usage for marketing or monetary gain.

Tradeoffs exist regarding exclusions and perceptions that should continue being evaluated. Anthropic appears committed to responsibly adapting requirements over time to maintain reliability while removing barriers to accessibility. With privacy and safety central to its purpose, any potential expanded use cases would prioritize individual user controls, transparency, and explicit consent.


Why does Claude AI require a phone number when other chatbots don’t?

Claude requires a valid phone number during signup to verify user identity and prevent duplicate accounts. This helps improve safety, avoid spambots, and uphold honesty by linking conversations to real individuals responsibly. Other chatbots may not prioritize identity validation or AI safety to the same level.

Does Claude or Anthropic have access to my actual phone number?

While Anthropic access phone numbers at signup for identity verification, the numbers are encrypted at rest and inaccessible to Claude’s AI itself. Only key moderation staff can access phone data with multiple approvals and this access is logged and reviewed.

Can I use Claude without providing my phone number?

Unfortunately Claude requires a valid phone number to complete the signup process so you cannot use the chatbot without identity verification via phone number. Anthropic may explore alternative validation approaches in the future.

Why does Claude need my phone number if I already provide an email address?

While Claude also asks for email addresses, phone numbers enable multifactor identity validation during signup and provide a secondary channel for responsible communications if ever necessary. Emails alone are not enough to uphold stringent AI safety protocols.

Will Anthropic ever contact me via phone call or text message?

Currently, Anthropic only uses phone numbers provided solely for identity verification and extreme cases of policy violations. In the future, with explicit user opt-in, notifications or 2-way communications could be enabled responsibly via phone channels.

Does providing my phone number mean I’ll get sales calls or spam?

Anthropic promises to never sell user data or use phone numbers for any sort of marketing purposes. Phone data access is minimized explicitly to improve AI safety and nothing more. Providing numbers will not lead to unwanted communications.

What if I don’t have an active phone number to use?

Unfortunately without an active phone number, you cannot create an account currently and would be unable to access Claude. Anthropic is exploring ways to responsibly expand access to more groups like younger users over time without jeopardizing AI safety.

Can I delete my phone number from Claude after creating an account?

While you can request deletion of your account and associated phone number, removing a validated number without replacing it with a new verified number would disable your account and prevent further usage.

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