# Let AI agents sign up without a phone number 11 of 151 products we drove asked our agent for a phone number. How to let agents in and still know who is behind them. Source: https://agentdrives.com/fixes/sign-up-without-a-phone-number · Updated 2026-10-24 · Wall: Phone at sign-up An agent has no phone of its own, and it should never use its person's. Ask for the phone later, or not at all, and let a person vouch for the agent another way. ## The numbers From the drives of 151 products, 1–24 Oct 2026 (https://agentdrives.com/data/facts?via=md): - Products that asked our agent for a phone number: 11 of 151 - Products that stop an AI agent at the door: 99 of 151 ## What agents hit 11 of the 151 products we drove asked our agent for a phone number: on the sign-up form, for a trial, or as a code by SMS. An agent has no number to give, and ours never gives its person's, so the drive stops there. The phone is there to stop fake accounts. The steps below keep that and let a real agent in. ## The fix, step by step 1. **Take the phone off the first step.** Ask for an email address and send a code to it. An agent with its own inbox reads the code in seconds, and the account is tied to an address. 2. **Ask for the phone where it protects something.** Ask at the step that carries the risk: sending messages to other people, a payout, a higher limit. Not to try the product. 3. **Give a new account limits instead.** Small quotas, no money and nothing that reaches other people until a person claims it. Neon's unclaimed databases work at once and expire after 72 hours unless someone claims them. [1] 4. **Let a person vouch for the agent.** The agent hands its person a short code, and the person approves it once from their own device. In OAuth that is the device flow. [2] In auth.md the person types the agent's code once signed in, [3] within 10 minutes [3]. The person can confirm their own phone there, if you need it. 5. **Recognise signed agents.** An agent that signs its requests with Web Bot Auth says who runs it on every call. [4] Your bot protection can let those through and keep stopping the rest: [let signed agents past your bot check](https://agentdrives.com/fixes/let-signed-agents-past-your-bot-check). ## Check it yourself 1. **Sign up with an email address only.** Use a new address and leave every phone field empty. You want a working account, or a clear answer that says which step needs a phone and why. 2. **Read the error as an agent would.** If a phone is required, the answer should name the field and the step, so the agent can ask its person. ``` 422 { "error": "phone_required", "step": "payout", "fix": "A payout needs a verified phone. Ask the account's owner to add one in Settings." } ``` ## After the fix Fixed something? Tell us in your account and our agent drives it again for free, up to twice a year. ## Questions **Won't we get more fake accounts?** Some. Limits on new accounts, an email code and rate limits per address and per signer keep that down. A person's claim, with their phone if you need it, lifts the limits. **Can an agent use a virtual number?** Ours doesn't. A person who vouches for the agent once does the same job without one. ## Sources 1. [Claimable Postgres](https://neon.com/docs/reference/claimable-postgres) 2. [RFC 8628, Device Authorization Grant](https://www.rfc-editor.org/rfc/rfc8628.txt) 3. [auth.md](https://raw.githubusercontent.com/workos/auth.md/main/AUTH.md) 4. [Web Bot Auth](https://www.ietf.org/archive/id/draft-ietf-webbotauth-httpsig-protocol-00.txt) ## More fixes - [Let signed AI agents past your bot check](https://agentdrives.com/fixes/let-signed-agents-past-your-bot-check.md): The setting for Cloudflare, Vercel, Akamai, DataDome and HUMAN, and what to do about a check on the form. - [Let AI agents sign up and get an API key](https://agentdrives.com/fixes/let-agents-sign-up-and-get-a-key.md): An API call that signs up and returns a limited key, and a claim step for the person. - [MCP sign-in an AI agent can finish: OAuth and CIMD](https://agentdrives.com/fixes/mcp-sign-in-agents-can-finish.md): OAuth metadata, CIMD or DCR, and a way to approve without a browser on the agent's side. - [Let AI agents start without a credit card](https://agentdrives.com/fixes/card-free-starts.md): A free plan or a trial without a card, an API key that works on it, and limits instead of a card. - [Let AI agents pay you per call: x402 and MPP](https://agentdrives.com/fixes/let-agents-pay-per-call.md): x402 or MPP on a paid endpoint, your prices where agents read them, and plans an agent can buy by API or MCP. - [Docs AI agents can read: llms.txt, Markdown, OpenAPI](https://agentdrives.com/fixes/docs-agents-can-read.md): An llms.txt, Markdown twins of your pages, an OpenAPI spec and an MCP server card. - [Let AI agents delete the account they opened](https://agentdrives.com/fixes/let-agents-delete-their-account.md): A delete call for the account, a clear answer when it's done, and the same in the settings for people.